Good thread Bruce!
Mine was an older spirits fired Mamod SE1a, acquired well over a decade ago, possibly over two, though it somehow feels like it has been much longer than that.
The Mamod was an accidental ebay find, that I was delighted with, as it took me back to my envious childhood days (daze) of the 1950's, when I was able to play with a neighbor and his nice Fleishmann steam engine with some few accessories. I don't recall the model number and am unsure exactly which model it may have been, but my memory and the old catalogs suggest it was a mid-sized double acting engine possibly in the 125 range (125/2?).
The real problem however, occurred while looking on-line for steam engine info, and happened to run across Indiana Rog's Temple of Steam, which totally amazed and initially inspired me. Rog very kindly mentored me some, and in an evil moment suggested that I might like to join a noted international steam Forum, to get a better feel for the subject.
The rest, as they say, is history!
Uncounted dollars, and well over 100 engines (I think?) later, and here I am today .... may the Steam Gods protect and forgive me?!?!