It's another fun part of the hobby, Anthony.
I took two Legacy GP7s, stripped them clean with alcohol and brake fluid, painted them orange and black with rattle cans made for models, and had Railgraphics make me decals for my fictitious "Chemical Coast RR of New Jersey" small, industrial railroad.
(The Chemical Coast Secondary was an actual industrial branch of Conrail, and I turned it into its own railroad, in my head.
It's been a long while, trying to find the photos. Turned out pretty good, with the additional details and mods to the stock Lionel engines.
What are you thinking of doing?
Jim