A number of years ago, the C&TS had magnetic overlays. They may not have been the correct dimensions but were close. In order to get around the rivet issue, Soni used a hole cutter just a bit larger than the rivet. We then hand painted the rivets white if necessary.
The frisket appearance was still there as the overlays did not have time to weather in.
Vinyl lettering might be the better choice, but the existing lettering on the tender would have to be removed, touch up paining done and then apply the new lettering. This is about a 24 hour job with two people, and then the RR would want the origional lettering restored.
Wouldn't it be easier if the locos and cabooses were all lettered Rio Grande? I know, that old can of worms.
Ron Burkhard