While many model railroaders build scale models from scratch, I'd never heard of that being done with tinplate - until I got some !! (totally by accident)
The North Shore Model Railroad Club (Wakefield, MA) is well known locally and is the place that people will dump old toy trains. To me falls the most interesting task of fixing and selling them. That's how the scratch built tinplate came to me.
This was a collection of about 20 cars, two locomotives and seven tenders, all painted in the Bellefonte Central color scheme - see the front car in the photo. It was a mix of Marx, Lionel and AF locos, tenders and cabooses along with mostly scratch built cars. By that, I mean cars actually built from sheet metal. The cars ahve a mix of AF and Lionel trucks. All of the couplers are the AF curly-Q style, but most of them are obviously copies hand made from sheet metal.
Here are some photos of what is left after selling several tenders and setting the locos aside for restoration
At the upper left you can see a Lionel tender. The collection included a Marx 333 and and an AF 401. Those two locomotives looked so bad that I coudl see no way to use or sell them other than to knock them down to parts, strip the paint and polish the copper and completely restore them.
See my topic "Restoring an AF 401" topic for more on that locomotive.
How did this set come to be ? I suspect it was a guy who wanted to have numerous locomotives and cars running on his Bellefont Central layout, couldn't afford to buy them and had the talent and imagination to build them himself.