1968 RS/SS L89

[1968 RS/SS L89]

How can I verify my '68 L89 Camaro is just that?
All the normal stuff lines up ie. casting numbers and dates, stampings, vin matches etc. It is one of those cases where everything is there but there are no docs. and I bought it at a time, the early 80's, when no one built fakes. Except of course 69 Z/28s, I think every '69 Camaro owner in Southern CA had been to GM and bought a tail panel and grill emblem back then. Point is when I bought this car no one was building fakes yet. Muscle cars were still being scraped at junk yards and cut up for drag racing.

I have been able to track down all the previous owners, I think. It was first purchased in Ohio and registered to a man in Cuyahoga Falls. Then made it's way to CA. and that owner did see the car in 2000. He had no paperwork but did remember it being an RS with the highest hp available for a 68 Camaro and mentioned something about those engines having no warranty?

So where would you guys go next? Are these vins getting to be like COPO where I could have it checked out or is that still a ways off, if ever.
Not interested in selling but I can provide other info to help.
Thanks, any help is appreciated.