Dave, yes that sure is me racing you in the 'Go Green' Challenger at the first Mopar Nats.
My seat covers have the same pattern as pictured above, but mine are defineately, defineately not leather, or have leather inserts. I've had a second opinion from a trimmer on that too.
Click here to view mine:
http://community.webshots.com/user/koolstude Look in the 'Temp' album.
Year One list a 1971 Challenger R/T with deluxe interor with a Belmont grain inserts & Coachman grain skirts, which are vinyl judging by the price. Could mine be these? Possibly seats have been changed, although I can't imagine that. Maybe it came with '71 seat covers, as the wheels too are 15" Rallye with the later centre caps. Also the colour I've been told the 'Go Green' paint is a rare colour on a '70 as this was a '71 colour.
Could it be a late '70 car? but according to fender tag, the scheduled production date was for 06/06/70