Thanks JDM.
I have to directly back off a couple of numbers I put out. I have a note that I observed #1149 on the White Pass in 2000, so that can't be right. I also looked at a sister car of 1130, and there would be rivets where there aren't any on 1130, so that's not your MOW.
On the other hand, there is this (again copyrighted) photo of one of the unknown cars in 1996: [
www.silverstatespecialties.com] . I think it is also the top car in the pile shown in your photos, except that the underlying numbers have not yet ghosted through. It's number is 117x (1170~1179). Eliminating all of the numbers that are otherwise "spoken for" in this range, it would either be 1175 or 1176. You can tell that the last digit is not a "5," so it would be 1176. The next car down doesn't reveal anything, except that the cone placement shows it to be a 35 ft. car. I assume that 1177 is at the bottom of the pile in the photos. And, I now don't have any ideas about the identity of the MOW car.
Robert