Reply to "How do you tell O Scale and Semi Scale products apart?"

@Bill DeBrooke posted:

Don't know about Lionel but MTH uses different boxes for different lines.  So do other manufacturers.  If you are buying new the catalog should tell you.  Part of the fun in this hobby is doing the research.  Info is available on line.

While I do my research, how do you tell the part numbers apart?
also when you are at a train show, which is where I get a lot of my trains there’s no way to tell the difference on the fly