Mike Steiner..500 Fanatic did the original build. We talked extensively after I bought it.  I've bought lots of stuff from him in the past, very good guy.
 He put a lot of very good work into it, especially the extra cylinder and case reinforcement..a well known weak area.  He sold it before he ever ran it.  Of course I just had to look inside when I got it.  I took it HPR for his opinion, He made some changes, we ran the motor...had to tear down again to fix the o-ring issue.  Its good to go now.   

P.S.  the compression release is a nice feature.........