It won't be for a while until I get to the wood and metal refinishing. I took the gun apart again tonight, and did a couple of minor replacements. The sear block spring and quad seal cup o-ring got replaced. I made up a poly tube transfer port for it. The two cemented together o-rings that were used as a seal were pretty flaked out.
The gun quit blowing air out the trigger group opening. 5 pumps now give me 460 fps. I'm still getting a velocity drop at 10 pumps- down to 430-440 fps. I'm probably going to have to think about this for a while.
Here's a look at the piston face:
And the valve face:
The valve looks just like a 13-XX valve on the front section. There's even a trigger guard screw hole on the side opposite the stock screw stud hole.
It looks like my repair options remaining are the following:
Go to a flat top piston.
Replace the valve check button and spring.
Replace the valve o-ring that goes over the threads on the body.
And replace the quad seal with a new one...
Regards,
Doc Sharptail