Taylor,
As it turns out I have more useless trivia to share. I finally looked at your photo more closeley. My guess is that the lettering is the original AC&F stenciling from 1904 (it looks alot like the lettering in car 3038) Note the square notch above the last number, with the round hole at the upper right corner. This is hwo the original wood carlines were attached to the top wall beams (for lack of a better word. The carlines had a "tab" cut into their ends that fit into the notch in the beam and then a metal rod ran through the round hole to pull the car sides together.
During the rebuild, some cars retained their top wall beams and got new metal carlines, which were attached by cutting a "T" shaped groove in the top of the baem that the carline could sit in. (as the photo shows. Perhaps the top wall beam now in car 3171 was recyled from another car that got new top wall beams. As an aside, car 3148 retains its wood car lines, but has had the notches for the "T" shaped metal carlines cut into the top wall beams, making it appear as though during the rebuilding, the new metal carlines were appilied before the old ones were removed and for some reason it was decided to allow 3148 to keep its wood carlines after someone went to the effort of preparing it for the metal ones.
Truly the end of the useless trivia for now.
Jason Midyette