MER convention cars

[banjobenne1]

Hello. I have two HO scale Main Line all wood kits in original boxes. One is prelettered for the 1946 MER convention and is mostly assembled. The other is prelettered for the 1964 MER convention, and is not assembled. What was the original intent with these cars? Would it be a sacrilrge to letter these cars for my home road? Am I supposed to run them as is? What if I just use the reporting marks and a number on the sides, on the car ends? What is the right way to prep the cars for paint (the ends, underbody, roof)? Should I use flat paint or glossy? How do I prep the strip wood? Remember these are wood kits modeling prototype wood cars. Ben