Christy Mathewson variation?
 

I would like your thoughts on this Mathewson signature. It is a small cut with a note saying "Here is an autograph that my (sic) answer your purpose. Yours truly Christy Mathewson"

It doesn't look like the traditional Mathewson signatures that are usually shown as exemplars. In Ron Keurajian's Reference Guide, he illustrates what he calls a variant of Mathewson's signature and here's how he says it:

"Starting in the early1910s Mathewson would pen some signatures in a smaller more practical hand. This form of signature, as illustrated in Mathewson 6, is vertical and may at times, exhibit a slight back slant. The hand is slower. The artistic flow is impaired. The signature has much less eye appeal. Why Mathewson signed in this fashion is unknown to me. Some have questioned the authenticity of this form of signature. Some have pronounced them as secretarial, but this is an incorrect conclusion. It is clear that both styles of signature were produced by the same hand. A couple of Mathewson handwritten letters and checks contain both types of handwriting. This dispels the theory that Mathewson 6 is a secretarial signature."

Attached is the illustration from his book showing a check (Mathewson 5) with both of types of handwriting and Mathewson 6 with the variant signature.

Also attached is a copy of a letter from Mathewson in 1917 that was stolen from the Hall of Fame. You can clearly see that the letter and the postscript at the bottom appear to be written by different persons. If you believe Keurajian, then both the letter and postscript was written by Mathewson.

I would ask you to compare the very unusual "th" in 'that' and the "a" in the 1917 letter with the 'th' in 'that' in the cut, as well as the formation of the letter "a".

I believe that the person who wrote the PS on the 1917 letter also wrote this note and signed it. Whether it is Christy Mathewson himself, or a secretary writing for him, I'm not sure, but I would like your thoughts.
Mathewson was college educated, so why he misspelled "may" is certainly puzzling.

I believe the note you are showing was written and signed by Mathewson. I also the believe the letter from 1917 was both written and signed by Mathewson, including the P.S. note.