Thanks for all the advice, and to Greg, Many thanks! I have printed that old insruction sheet, complete with castor stains and creases. That will be a big help. By the looks of this engine it has not been run much at all and judging from the brown castor baked into the piston, it was run on the proper fuel. The compression seal is very good, with barely any leakdown. This is a ebay engine and I can't help but wonder how many of these listed there (I see many) have been run on a modern synth fuel and trashed.
My mission now is to find a #703 muffler or something else suitable to qiuet the engine. I know these engines were run with open exhaust often back in the day, but wow, the noise must have been deafening.

Mike