I get some of my diecast from Supercars website. This is their Challenger listing right now (including their archive) http://www.supercar1.com/catalog/index. ... cription=1
There are several pages of Challengers, and as this includes their archive,some are sold out so you may have to find another dealer.
Another dealer, Kevin's Hobbies, has a pretty good selection of cars also. Here is his Challenger listings http://www.scale18.com/cgi-bin/page/bro ... %2A&c2=%2A
I don't have your Challenger as of yet. I've got somewhere around 15 or so Challengers right now and am looking to add one or two more.
Supercars (what yours is, I believe) usually details out a regular production diecast. They are rather nice. The newer molds are more authentic than the older molds. The older molds have dogleg hinges, unrealistic hood hinging, auto transmission underneath whether car was stick or auto etc. The newer molds are better in those details.
I think that's the only one of your car right now but I'll keep an eye out for any others.
edited to add that Highway 61 is bringing out a '70 R/T in Sunfire (?) Yellow http://www.ffertl3.com/products.cfm?productID=43605