I'm not positive if Matt knows, but he may. Call up or ask Motor West Inc break>
He deals with many Puchs. Oh and fuel, for sure would mix 50 to 1 with Amsoil Synthetic, and run the best that way for it. I'd say that thing should do about 40 to 45 mph maybe more. I could be mistaken though.
There should be a Sears and Roebuck tag/emblem rivited to it somewhere. That's the # ya want for a year. I don't know how to tell the years on those, but Matt may be able to look it up.
Looks like ya got a ways to go to make it original again.