Problem solved. I keep a glass platen from an old copier covered with 320 grit sandpaper. I use it to flatten parts like carb flanges, etc. I dressed the copper gasket flat. Thickness varied from 0.0265" to 0.028. That seemed good. Did the same with the ring on the head - just enough to know there were no high spots. I then annealed the gasket, dressed it with Never sieze, and bolted the head in place. Voila!......It still didn't hold pressure. So I held my face real close and felt the air coming out of somewhere - turns out there is an impulse passage going to the fuel pump gasket surface for those models with auto oiling. I still had the oil pump cover off so it leaked. All back together now and no leaks, holding pressure fine. So here's the crankcase and cyl assembly. Hmmmm wonder if anyone ever nicknamed this thing "The Turtle?"
btw - the blue arrow in the bottom photo points to the bushing I turned to reduce the seal opening so I could use the same seal as my SP125.
Edit - thought I may as well throw in a "before" photo.
