Is Seacraft 19 a Classic?

[tommyg29]

Hello, first post here but been lurking a while and have read a lot. A SC 20 has been my favorite boat since the 70s, but have only owned an Aquasport. Been boatless for a while though. Looking to get back in the game now that the kids are finally all about out of college, and have a couple questions.
Ive come across a few Seacrafts described as "19"s but listed at 20' with upgraded decks and CC's. Are these converted bow riders? And if so are they considered "Classics"?
I have a heavy automotive background, and a LOT of people in the collector auto market think it blasphemous to try to improve on or update a classic, but many classic Seacrafts have been heavily modified, so it seems this community is a generous and understanding bunch.
What Im also asking is, how are the Moesly and Potter years defined, and the overlap years of 68-70? If a Potter built hull is one from 1968 to 1980, then is a Classic Seacraft one from 1961 to 1980?
And a one off question....which years used the older aluminum "SeaCraft Classic" emblems on the side?
Thanks for your help.