i did not know about that last one. Thanks RRSignal
as far as locomotives go as mentioned above Jointed Rail sells a 3 pack for $10. I'm planning on buying one, anyway USLW has a horizon coach reskin into MBTA colors. If your one of the fortunate people that got their hands on Connyxy Bilevels you could reskin that into an MBTA Bilevel. Sportsguy on Trainz Commuter Rail has a set of Bombardier Bilevels in MBTA colors. And there was a set of MBTA loco's that included an F40PH, GP40, and F7 in MBTA colors. They also featured the lightning bolt scheme, but to my regret i can not remember where i got those trains. And i unfortunately lost them in a computer crash. So overall
MBTA Single Level Coach/Cab ------------ Milkyoreo27's site
MBTA Bi-levels ---------------- Sportguys Site (Trainz Commuter Rail should have a link)
MBTA Bi-Levels ---------------- Art Train site
MBTA Horizon Coah ------------ USLW
MBTA F40 Pack ----------------- Jointed Rail 3 pack $10
and if your lucky and have Connyxy's Bilevel reskin that into an MBTA did. Which i have done several times.