Well ....Yes and No, He and I mildly disagree at present as to the authenticity of all three of what I would consider "knowns"...legit signatures of Joss. The example I cite from the widow might not even exist anymore as it appears to be an old style xerox , so she might have just sent out the copy and not the original. Or maybe only had a copy herself.
Then you add the intangibles of the signature variations , and rarity which would (I hope) make anyone who trys to authenticate an Addie Joss signature be looking at more than just "slant, formation, pen pressure etc etc, blah blah" and be instead looking for ROCK SOLID provenance and the ability to back track what? Almost 100 years to practically "put the pen in his hand" Anything less would be negligent considering what his signature would sell for either via auction or outright sale.
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jim@stinsonsports.com