Greg & Company,
This is an interesting thread, covering the gamut of art and human behavior!
I'm not a lawyer, so cannot speak with absolute confidence, but a photographic image of an object, or a painting of an object is copyrighted, merely by the act of making the image, but the object itself cannot be copyrighted by the owner of the object.
Witness all the spy photos of new cars that appear in the car magazines. As long as the photo is taken from public property, the car companies cannot block publication of a photo. If that photo was taken on company property, then it's a different matter. The same applies to railroads. If you go onto private property to film an engine, the property owner can control your ability to profit from the image. If you took the picture from public property, he cannot.
Regarding the claim that a copyrighted name on the tender allowed the owner to prevent you from using an image, I suspect that the courts would regard that as incidental, if you had taken the video from public property. Certainly, Trains, Railfan and other magazines don't contact NS, CSX or any other railroad each time they publish a photo. If, on the other hand, you have a recognizable image of a person in your photo, you will need a signed model release, unless the photo is being used in a news situation.
All that having been said, it is good business for both video makers and museum groups to get together and support each other. I feel that the video maker wouldn't have a product to sell, without the museum having the engine, and the video maker can provide great publicity for the museum. I think something like a voluntary royalty agreement is probably the most sensible way to do it.
I note that Greg has often offered to give a portion of his tape sales to the "Friends". This is as it should be. John's wilingness to give some prints to the locomotive owner is another example. Both sides profit from each other's endeavors!