Pete, the S 600 I drove was, I think, a 64 model. I have seen quite a few S 800's in the late 60's and early 70's that were used extensively in the SCCA D/SR class. That's back when many, if not most, of the small sports racers were still engineered and built by individuals in their "garages"...great little engines and, led the way until the two cycle motorcycle engines began to rule. Haven't seen one in a lotta years.
Oh yeah, the one on E Bay is in NZ and is really low mileage and CHEAP...if I was anywhere close, I'd own it!
Rod