If you guys can find a way to obtain this poster from artist David Kimball, that would give you a lot to work with. There are many sources on the Net to purchase one from.
I looked at your model car renditions and it looks like you have patterned a Factory Five Racing body style vs. an original (the squashed fenders in the rear are the tip-off for me). If you're trying to map an original CSX car then I would look for ways to flatten that out a bit.
Also the ERA web site has some really great references:
http://www.erareplicas.com/427/cindex.htm
http://www.erareplicas.com/427/profiles/index.htm
Good luck!
-Dean