Continuing on... Here is a better view of the underside of the top plate. Note that the gears do ride against this plate somewhat, but not nearly so much as the lower plate, because of gravity. (This is one of many reasons why running a Cirkut upside down might not work as well ;-) ) So definitely oil those spots when reassembling, but for routine maintenance, the idea that you can just oil the easily accessible lower gear shaft points is actually a sound one.
Here is another view of everything in this state of disassembly. Note the pointy bottom of the governor shaft. I guess because it spins so fast they didn't want the flat bearing surfaces like with all the other gears, even with washers. It's a tiny point that goes down into an even tinier hole. Remember that the top mounting of the governor is also a point (on the end of the screw that goes down into the top of the governor shaft.) This is why you definitely want to set that top screw so there's a little end play. If you crank it down too hard you'll be pushing all these points into smaller holes and wedging them.
Here's what the bottom plate looks like with the gears removed:
Here is the underside view of those removed gears. Note once again on that same gear as before, there's a thin washer to keep track of.
I didn't take any more pictures because my hands got really dirty from here on out, but what I did is this: I used very fine (00 or 000) steel wool to polish around all the bearing points on the plates. While I was at it I also polished all those corrosion spots, just because they looked so bad. When I was oiling everything else, I also spread a very thin film of oil on the plates to try to limit future corrosion (at some potential cost of attracting dirt...) I was using gun oil and it's the same principle as with a gun - you want the oil there not only to lubricate, but also to prevent corrosion. I cleaned and oiled the shaft for the governor brake (the one with the spring around it in the above pictures) in place - I didn't try to disassemble it, because that spring is so strong, and it therefore only needed to be pretty clean and decently oiled to result in working perfectly. I cleaned and very lightly oiled the bearing surfaces of the gears (the shiny silver parts near the shafts) and any washers. By lightly oiled I mean I put a little gun oil on there and then rubbed it around with a Q-tip, which had the benefit of mopping up any excess.
Putting the top plate back on is tricky. First get the 3 big main gears down on the bottom plate. Then holding the upper plate sideways, put the small gear in place up against the governor in the top plate and hold it in place. Now tip the bottom plate up nearly sideways to match (not fully 90 degrees though, or the big gears fall off!) and feed the top plate down onto the 3 long posts, and then onto the 3 shorter posts, all while not dropping that small gear, and at some point using your third hand (!) to pull the brake back out of the way. It's fiddly but it can be done. Then once it's almost all the way together, you reach in and scoot the small gear and the governor around until they actually seat in their holes in the bottom plate. Hold it together and make sure everything spins (when the brake is released), then keep holding it together while replacing the 6 nuts that hold on the top plate.
Now clean and oil the bottom of the spring housing and those 2 washers and feed it into place on the bottom plate - made easier again if you hold it sideway so the washers don't just fall off. You'll need to fiddle with the ratchet pawl there because it will want to just flop into the way, but once the motor housing is most of the way down you can reach in with a small screwdriver and push the pawl back and forth until the spring housing drops down into position. Then replace the round cover plate and its 3 nuts. Now you can do a little basic testing of the motor. You can wind it up a bit, push the brake lever out of the way and see that everything spins properly. If you took apart the top bearing screw on the governor now is a good time to readjust it. Then you're ready to put it all back together. Insert the inner half of the on/off switch shaft, the part that actuates the slit flap, into its hole in the top plate, with its actuating arm straight up. Insert the fuzzy-headed speed limiting pawl thingy down into its slot near the governor, pushed all the way down until it contacts the governor plate. Feed the motor back into the camera body while holding it upright, making sure the drum (which is just flopping around) is in position to let the spring housing come up into it, and the slit flap actuating arm on the motor clears into its hole in center of the body. Now install 3 or 4 of the 12 screws that hold the motor in, to hold it in place.
Hold the film drum with the film latch facing you, so you can see down into where the setscrew will go. Run the motor (by pulling back on the brake lever with your finger) until the setscrew hole in the spring housing is facing you. Now feed the long shaft back down through the drum. You'll have to wiggle it inside the drum until it feeds through the bottom hub of the drum, and then you'll have to wiggle the drum until the shaft can feed on down into the hub of the spring housing. Once there, spin the shaft until you can see its hole down through the hub's setscrew hole. Now you have to install the setscrew, which is a little tricky. I used a dab of sticky glue on the top of the screw, to make it stick to the screwdriver while I lowered it down into place. You need lots of light to see what you're doing here. Once it's there you can carefully start screwing it in, making sure it's not cross threaded. Odds are it will bottom out almost immediately - don't force it! That's because the hole in the shaft isn't really lined up quite right. While very gently trying to tighten the screw (almost no pressure at all, just the tiniest bit), just wiggle the shaft back and forth the tiniest bit...at some point, you should feel the resistance go away, as the setscrew pin heads down into the shaft hole. Keep doing that until the setscrew really does bottom out and is secure. At that point it's still above the hub quite a bit. This isn't one of those setscrews that ends up recessed into its hole in the hub. Now replace the spring, knurled plate, and knob on the top of that shaft.
Now feed the on/off switch and shaft in through the side of the camera body and through the boss on the motor top plate, until it starts to engage with the other half of the shaft. You need to push and wiggle until its seated fully. Spin the switch on the outside until the holes line up and you can feed the tiny pin back in, pointy end first. Once I got it in just a bit, I turned the switch about halfway, so that I could take small needlenose pliers and press the pin down in fully, by putting one side of the pliers on the pin, and the other side on the other side of the shaft. Once that's done, spin it on and off to make sure it works, that the slit flap is opening and closing, etc.
Now comes the fun part. Getting the speed switch all back together right. Here's how I did it; perhaps there is a better way. Slide the geared shaft down through the hole, with the square end squared up with the camera body, until you feel it engage with the gear and slide fully in. Then, without installing the screw for the lever, just put the lever on the shaft (which should leave it pointing just below the 1/2 setting) and then spin it up to the 1/2 setting. If everything went well, that's correct. Odds are everything didn't go well. Wind up the motor and test the speeds to see if 1/2 is really 1/2 and 1/12 is really 1/12. If the speeds are too fast then you need to set the pointer to 1/2, remove the lever, then carefully, oh so carefully, pull the shaft up out of mesh with the gear (I used needlenose pliers), spin it counterclockwise one tooth, then push it back in mesh with the gear, then retest. If it was going too slow, same thing but spin it clockwise one tooth before reinserting. The problem comes when you think you're reinserting it one tooth off but what really happens is the limiting pawl moves a tooth too and you're just back in the same spot you were before. Eventually you'll get it right. Well, eventually I did, I can't promise for you! Then remove the lever, reinstall the plate that secures the shaft in place on the body, and the two screws that hold it. Replace the lever and its one screw. Replace the rest of the 12 screws on the bottom plate. You're done! Go shoot some pictures.
Oh yeah, how does one test the speeds you ask? I have a document that explains it, let me ask permission from the author before reposting it here.
Duncan