I'm not giving up on this one yet. My plan is to ride it like a mix between "slow enduro" and "free in the woods trial", like a cheap version of an Ossa Explorer or similar. I'll hardly be riding any challanging, pure trials with it.
The brake is now ok after adding new fluid and purging air.
The clutch is ok. The friction discs and the plain discs were almost "glued" together by old sticky oil. Took it apart and cleaned it up and it now engages and releases as supposed (I suppose). Couldn't find a torque value for the clutch spring bolts so I used 12 Nm. Anyone knows?
I have new seals for the forks but the dust caps seem unavalable. I guess I just have to use the old ones which seem fine and maybe use neoprene protectors in addition.
The rear shock are now in parts. Small pieces of the internal "punch through" rubber had came loose and were jammed in the valve. I accidently spilled most of the oil when I took it apart and I don't know how much oil to add. There is a separate chamber in the tube, I dont know if it's nitrogen filled, air filled or just spring loaded. There is no schrader valve or similar to refill it with (if air or nitrogen) but it's very springy and if gas filled it doesn't leak. Should the oil chamber be entirely filled when gas chamber is fully compressed? There does not seem to be a spec avalable for this shock so whats's generally the idea? When looking on rebuild videos of shocks with external gas bladder they seem to fill fully with oil before adding nitrogen.