The Pony Express is something I've always been intriqued by - as you can tell from my avatar. Some years ago I wanted a Pony Express stamp. I bought a nice looking one from Spink. Unfortunately, at the time, I didn't know what I was doing and didn't know about forgeries. A couple years ago I got Larry Lyons locals books and saw quickly that it was not an original.
I finally got around to trying to figure out which fake it is. I think it is forgery D.
I went through all ten clues in his book, and it certainly seems to match. It says in the book that forgery D is Frajola's 1WE1F5. I'm not sure that that code refers to, but if Richard is around maybe he will explain.
If anyone is brave enough to check me, feel free. Otherwise consider this just a word to the wise.