If they are indeed models and your collection also contains toy trains then you want to be sure to differentiate between the two. We added to our PastPerfect Lexicon under Recreational Artifacts, 'Model, Train'. For any parts, accessories, buildings, etc we have additional primary and secondary terms specifically for those.

Then under the object title we specify whether it is a car, locomotive, building, type of part, etc. Hope this helps!

Best,

Alex Kron

Curator of Collections

San Diego Model Railroad Museum