Fujica Drive front focus element became stuck all of a sudden

[fabulousrice]

I took the Fujica Drive out to shoot today, and it had been working ok but the aperture ring was stuck on "A" and therefore the speeds ring was not usable, but the focus ring was moving smoothly so I didn't mind it being stuck on automatic.

And after shooting around 12 pictures, the focus ring started becoming difficult to move and now it's completely stuck. I tried with (padded) pliers and couldn't budge it.
I didn't want to do anything that might damage it so I'm asking here. In the process, I was trying to move the aperture ring and got it to losen up so now the aperture and speeds rings are usable, but not the focus ring...
Annoying that I can't seem to get everything to work at the same time. I'm assuming there's some sort of gunk floating around behind the rings that gets to all the wrong places and prevents operation.

I don't know if it's possible at all to take it apart (the film gate is so small that none of the tools I have could fit in there) and I'm hesitating to oil it.
I'm just surprised because after using hundreds of cameras, lens rings usually become smoother the more you use them - not stiffer.
I wasn't able to find a repair or disassembly guide anywhere online.

It's super frustrating as I've put a couple of rolls of film through it before and was able to focus each time...