Thanks Brett. You make it sound so straightforward that I may need to buy another off ebay just to try tearing down myself.
But...it will have to wait on the Pentax SV I already have in pieces on the workbench.
Well there is a little more to it than that which I didn't mention for brevity: the centre lens cell must be unscrewed to reach the front of the shutter. Unlike later models the early ones won't usually be too hard to remove, inverting the camera body onto a rubber mat and twisting will usually do the trick. And the stop down spring for the automatic aperture will de-tension itself when the shutter is removed from the body, but it's not a weak point. It won't break as the shutter is pulled, or, when it is re-installed. You just need to reach the locking screw for the adjuster wheel (sort of like a star wheel inside a corner of the body that you've got to access via the film gate). You'd quite likely want to sacrifice a cheap screwdriver or two to put some bends near the tips, because it is quite impossible to get a driver straight down onto them due to their location. But that's the only difficult aspect. Once you've pulled the locking screw and backed off the retaining screw (in the centre of the adjusting wheel) a little, you simply set the aperture control to f/22, gently rotate the adjuster until the blades have fully stopped down, and then turn it another two or three teeth, until prompt and consistent stopping down is confirmed by inspecting the aperture operation through the film gate as the shutter is fired at various speeds (notably the 1/500 and one second). You can actually leave the locking screw out while you're doing the checks, it's just a safety feature, the retaining screw keeps the adjuster fast once it's nipped up.
When the shutter goes in the actuating rings have to mesh correctly with their counterparts at the back of the shutter. Yes, you could install them wrongly and it wouldn't fire, but, again, if you are paying attention to the location of the parts when the shutter is removed, initially (of course a few digital reference photos never go astray) it's not very hard to establish how it all re-assembles. To me it's not as hard as re-timing an overhead camshaft engine, for instance, and having done a few of those, including early desmo Ducati motors, Citroen flat fours and other ephemera I do speak from some experience there. All these things happen with the body uncocked, by the way, quite apart from any other considerations, you couldn't reach the stop down spring adjuster or the retaining ring for the shutter with the camera cocked, anyway, as the rear capping plate and mirror would be in the way. Speaking of the mirror it is of course a good idea to give that a clean when the shutter is out, and the focus screen also, if it needs it. Those clever designers at Zeiss did include a small access port on the rewind side of the body near the rewind fork, so, if you really need to you can sneak into the mirror box this way to clean a mirror but, the access is very restricted and it is much easier to attend to any cleaning through the front when the shutter is out.
You might recall that Phil (farlymac) actually had to to do some work to a Contaflex II a couple of years or so ago, and he had a good thread with some information and photos which I added some comments to at the time over at RFF. If you were thinking of taking on a service to one (and other issues are not entirely unknown, but, servicing is almost always all that they need to function nicely) then, that thread is also worth a look. The repair manual for the C1-IV is out there on the web as a free download (KY Photo site, perhaps?) or, it was, anyway. If you need a copy of it I can arrange that and if you get stuck of course I can probably offer some suggestions.
Cheers,
Brett