Eric,
Way back in 1996 I was riding my motorcycle up to Montreal for the F-1 race. I stayed in a campbround a few miles south of city and very near there was a railroad museum. I'm sorry I can't remember the name of that town or the museum, but it was a fairly big one - probably a "national" rr museum of some sort.
Anyway... the had quite a bit of "Newfie" stuff there, an ALCO diesel, some freight cars, and, unless my memory deceives me, a tank car that looked very much like the familiar UTLX narrow frame / frameless tank cars used in Colorado. I don't remember seeing passenger cars. All this stuff was from the 42" Newfoundland line.
I would bet that if you could track down this museum and their staff, they could help you out. I just did a quick web search, but didn't have any luck finding it.
Later, Gary