FOOD FOR THOUGHT
Good storage idea. For aesthetic purposes one could have used some cheap rattle can black paint on the new shelves or some dark stain product. Most handymen have leftover paints & stains lurking on a shelf somewhere. I see that you used real wood for the shelving not the particle board stuff. Less warpage with real wood than particle board. Real wood takes color better than PB. With so many engines how do you keep track of each one? Especially if one has multiple examples of the exact same engine. To keep the engines from collecting so much dust. One could install a plain curtain on the bookcase or a custom personalize one with RR Logos or your own BENZ TRAINS logo. 99% of my train rolling stock items are stored in BCW 5000 Monster boxes that I customize for each train item. These boxes bring in a whole new way of thinking on how to store them.
Just some random thoughts here.
LATER