None of my `British` stock is actually correct for the Country Peter, apart from the colours. British Railways never used tram-style driving trailers or small USA steam locomotives to work with them as push-pull. Total fiction, but I love them and that is all that matters. I am not trying to re-create anything.
As you correctly guessed the body is made from a pair of LGB four wheel tram bodies, with one end removed from each, and then joined together onto a scratchbuilt underframe.
The original bodies were bought off the Internet without running gear, I didnt scrap a working tram!