Dear Sirs, I don't know what city Mr. Sellios' layout is in, but I deeply apologize for opening this can of worms...
I did some research and those aren't F units at all. They could be experimental gas-turbo-electric units powered by the A. Zol Co., of Franklin. They failed to operate well, and the carbodies were bought by EMD and re-engined for the first FT's. On the other hand, it is also possible that you are seeing evidence of the secret 'Boston Experiment', involving the teleportation of a freight train, which as you all know went horribly wrong. I assure you my sources are very reliable, and would gladly refer you to them, only I can't reveal their names...
Anyhow, I feel there is no such thing as an anachronism, since I just made 4 BLUE PRINTS today.
Cordially yours, Gerard P. ____ | ## | |_##_| _ _ _ _ _