my first try with Imgur, but it seems to work.
First pictue is the underneath. To use the F clamp I just drilled out the rivet on the fixed end.
Second picture is all the pieces spread out.
Third picture is it all together and the fourth is the same plus an extra F clamp I have to show what I started with. The two vertical pins are just carriage bolts with 1/4" fuel line to protect the gun. The cable tie is the re-usable type, and the shims are to accommodate different guns. The flat piece is to accommodate any rifles that you have to compress from the end of the barrel, or that you have the barrel off.
Fifth picture is the compressor with the action from my Quest loaded. Normally I would remove the rear sight, the Picatinny rail and the plastic end cap.
I've used this compressor many times without "mis-hap" on every (except one) springer I own, including my Diana 30, XS28M, XS46U etc. On the 46U I use a 1/4" x 2" hex head bolt with two nuts on the open end and I put it through the gap in the plastic end piece then attach the nuts. The punches are to push the pins out, and I use them to substitute for a pin momentarily during re-assembly.
I recently acquired an XSB26 which works perfectly, but eventually (probably just due to my curiosity - I've already had its "Rekord" trigger apart because I felt like it) it too will fall prey to my compressor.
The whole thing hangs unobtrusively on the wall of my garage when not in use. Having it gives me a good feeling that if I decide to take a gun apart again, there won't be any drama. I'm too old for drama.
Peter