This just a small suggestion, but I'd personally like to see the Thomas model have a variant that has no face on it. So I could add it to other custom scenarios with our his face standing out. Just like a normal tank engine.
This has actually been suggested in the various Thomas threads - give the mature train simmers an authentic E2 tank with correct physics, well as much as TSW can manage. The down side is that none survived into preservation so would still be a bit of artistic licence putting in the game.