Dave,
Your GP7 NP colors are incorrect on your layout, the original NP GP7 colors are on the GP7 in my attachment, the work caboose also. The Union Switch & Signal made them. I love the original NP passenger cars also, they however were made by somebody else, a might later. I believe your NP engine may be a later version, with the changed coloring. Still very cool however!
PCRR/Dave
The Lionel NP Christmas Box Car Train, with original NP Caboose.
