I sent Scot Mann an email last night asking if there where any M1's available, and if not, any plans to rerun the engine, so far no reply.
I believe Scott may still be in China, thus his replies to you may be at odd times. However, I can tell you that Scott RARELY does reruns of steam locomotive models. You may just have to resort to watching eBay for a 3-Rail model to popup.
I would be reluctant to try to re identify an engine. Also, I have a GGD and 7 Lionel engines all running via TMCC would a MTH run in that environment or would I have to wire up a TIU? Thanks for all the info, very informative so far.