A few years ago, I started adding a lot of my railroad car detail shots of fallen flag heralds (such as Illinois Central or Southern Railway) or graffiti shots. At first they just sat there, but lately I have been selling them here and there. Just this week, I made an unusual sale. They wanted an original, high resolution version of a shot in particular so they could see all the details in the graffiti art so they could make an N scale model of that boxcar. It is stipulated that all the will do is use the photograph for seeing the detail and not for promotion afterwards. I was paid, of course, but they're also sending me one of the cars they produce from it. (I model HO scale, but it will be cool to have nonetheless.
I guess they found me doing a Google search which is why for folks that shoot railroads it is important to put the railroad name and reporting marks in the tags. These are supposed to be visible on the car, engine or caboose. For example, another recent sale I made was of the Southern Railway #630 steam engine because the buyer and her fathr used to see that engine back in the 50s running through North Carolina. I don't know how she searched for it, but "Southern 630" or "SOU 630" eventually got her to me. And I'm very glad. So, in closin, railroad name or reporting marks and car number are very important in tagging train scenes.
(I actually suspect she looked for SOU 630 North Carolina which brought her to my images. Location is obviously important to