I second the shout out for David Schimel. I recently got a Schimel repair manual, two seal kits, and a new set of grips from him. David is a great guy to work with!
These guns are made of pot metal (delicate) and held together with knurled push-pins. This can make disassembly and reassembly a bit tricky without breaking anything. Consequently, I ground the knurls down enough to allow the pins to be reinstalled with only a light tap of a small hammer. Good enough, and everything holds together. Note that the pins come out from the right hand side and go back in the same way.
Some of the seals can be had from industrial suppliers like McMaster-Carr. Last year I replaced the CO2 cap O-ring and the cup seals on one of my guns with an O-ring and hydraulic cup seals from McMaster. These are not going to be direct drop-in parts. The cup seals from McMaster needed some re-sizing to fit (spun in a lathe or drill and sanded down, both the ID and OD), note that the ID must be tapered for the sliding seal (one cup seal is stationary while the other is required to slide). I will save the specialty seals from David for the more critical sliding seal, and use the reworked seals from McMaster for the stationary seal.
The CO2 chamber is secured by either a set screw or pinch bolt (depending on the gun). Neither of these appealed to me, and IMO were a design flaw that seemed to invite damage. Both my guns have a precision spacer between the CO2 chamber and the slider it screws into. Any subsequent adjustments are made using 0.010" ring shims (each is roughly equivalent to 1/4 of a turn of the chamber). CO2 chamber is tightened by hand, that seems to be good enough.
So far, so good.
I love shooting these things. Almost sounds like a .22 short .... loud. And surprisingly accurate.
