That so-called "Santa Fe font" is a lettering style created by the AT&SF drafting department a long time ago. The Erieroman font someone posted was created by someone who based it on the Erie's extended Roman lettering style, which came out of its drafting department. At best it's only similar to the AT&SF's. In fact all extended RR Roman letter is similar, but I can tell you from personal experience that the extended Roman used by the SP, Santa Fe, and WP all have stylistic differences from each other, some subtle others not. Adding to everyone's confusion are the slight variations introduced by the painters when the lettering is done by hand with a brush.

"Font" is a printer's term, and the RRs used lettering styles because the lettering was hand painted, not printed with a press. Modern usage of Roman lettering started with this:
[books.google.com]
All the varieties of extended RR Roman owe their origins to this. It's in the public domain because it was published before 1918 -- in 1535 to be exact.