Originally Posted by joe sch
In general, any player racket should have a Certificate of Authenticity (COA) verifying the source/story. The Bosworth collection rackets often have tags identifying them to players but its not a published or explained type of identification. You could keep your TW receipt as part of the source verification and the TW description.
if TW writes a letter of provenance, stating explicitly that Warren Bosworth has told them, that the racket was not only customized for but also actually played by TM, that might be good enough. an actual letter from Bosworth himself would definitely be better.