Max
Suggest buy a parts Kiev, a set of watchmakers screw drivers, and pair of small needle pointed pliers, a small file, a blower bubble for cleaning, a tube of liquid PTFE lube & then fix the parts camera. Then when the parts camera works 100%, fix your IIa. you need a deep tray, a notebook and double sided tape as well. A set of 10x8 trays allows contact prints to be processed for filing as well as stripping a camera, and lens. the note book and double sided tape are really essential.
The investement should should be less than postage if you can get some second hand.
The only rule is post a query before breaking anything. A magnet and vacuum cleaner are useful is you drop a grub screw, most of the Kiev ia ferromagnetic steel.
Noel
PS. You grind the ends of the pliers as a lens spanner first, so you can strip the J8 you get with the parts camera for dust or fungus.
PPS. I normally use my parts camera in preference to a collectors piece like your IIa.