I wish I hadn't looked at your tinplate photos and videos this week. Now, I have to have a tinplate train!
In checking Ebay, and my local flea market, it looks like Marx rules if you want inexpensive used cars, and don't particularly care about the RR line or small features, just colorful cars.
What would you say are the Three most important things I need to check before buying a Marx car please. (I don't care about resale or collection value.) As always, I am kinda worried about coupler compatibility.
Thanks very much for all advice.