Okay, I'm pretty sure that someone mentioned Motor West when you posted about the first one of these that you got. They have old Puch parts - mostly for MoPeds and twingle-engined bikes - but they probably have engine parts for yours.
The date is famously hard to determine. These are catalogue bikes - they were sold in the Sears catalogue and on the Sears sales floor. If a bike didn't sell one year, they just sold it the next; the dates on the titles mean very little.
The up-side is that they sold the same bikes for years and years - most of the time you can just purchase a part for the right model without worrying about the year.
P.S. - If you call Motor West, ask Matt if these scooters use the same engine as anything else (the Sabre, perhaps).