I had a 175 myself that I rode in Vinduros for a while, sold it now and run a 250
The 175 was a great fun bike, they weren't all that rare, they made them for about 3 years depending on what country info you look up but they are all basically the same.
I think the kick start dogs are fine but its hard to tell from the picture, the missing washer goes over the shaft so it won't fall through the hole, this will effect the tensions on the spring etc, its only thin maybe 1mm
The bolt holding the kickstart knuckle looks too long, its not catching on the case is it?
The clutch washers are probably to increase the clutch spring pressure to stop a slipping clutch, with bush engineering you never really know if they are needed or it was misdiagnosed as the problem.
Grooves in the outer clutch basket fingers often cause sticking plates.
I stock a few Kawasaki parts, I have replacement rear guards and headlight shrouds in stock, maybe cables, I would have to check the 'warehouse' to see what is still there.
I think I have a spare frame still, it may have the sidestand lug on it still, will have to check. You would need to find someone to weld it on the frame for you.
Finding a sidestand will be the hard part.
The wheels don't normally fall off, old mate should have been afraid of working on it, not from riding it!