Anyone know where I can buy an HO scale GP39-2 High Cab Loco, or how to kitbash one?
I assume you are referring to the “Kennecott Copper” units. I would start with a Cannon products EMD cab, and modify the high mounting with extra cannon parts. I am not aware of any models, brass or plastic, that are available. Look through a Walthers catalog, you will find all you need right there. Photos of the prototype will guide you through the project.
Todd C.