Warren,
Back in the early 90s, Likelife started their proto series of models one of which was a GP18. They actually did the Central of Georgia in the Southern paint scheme with CofG sublettering. This product line ultimately was picked up by Walthers. I don't believe Walthers has produced the GP18. Atheran has a GP18 model now so maybe you should consider contacting them. Also since Atlas is doing another run of TAG 80, maybe they could be talked into doing the GP7s again.
Charlie
