I just got done checking a letter written to Teddy Roosevelt in 1901 which had the usual fuzzy signature in otherwise really good cursive. The previous transcriber did a great job but had to guess the last name was Mason Michael, or something.
A clue can be found in the context of the letter, however. The writer referred to "my old wound" which is something soldiers-in-arms tend to talk about, and this made me think it might be a good idea to check and see if this was one of Teddy's old Spanish American War buddies dropping him a line from Hawaii.
Sure enough, on the roster of Rough Riders there a Mason Mitchell, a nice guy who, apparently, writes a double-l with the first l so short it looks like an e.
You can find a link to the rough riders names by clicking here (click!):
I tagged the letter with the name, with "Rough Riders" and the usual indecipherable shorthand.
I can also recommend Teddy Roosevelt's book about the Rough Riders. Great read.