So I want 2000 GT door panels in my 1970.

[jwboner]

I don't know if you would be able to retro the new panels to fit the old doors, but you might try fabricating some. Make a cardboard template of an old panel, then copy it onto something thin and rigid and stretch vinyl or whatever you want over it putting any accent markings on it as you go. I thought about going this route with mine because I didn't really want to go with the plain looking panels that it came with but it would have taken too long so just went with some new stock ones.
John