I happened to find a bat Goodwill that I knew right away had Mets players. So far, I've identified:
Bobby Wine
Felix Millan
Ed Charles
Joel Youngblood
Jerry Grote
Buzz Capra
Pat Zachry
Duffy Dyer
Tim Foli
These guys are spread over several decades so I know this was from a true fan. Two signatures remain undiscovered. I've used ultimatemets.com as a starting point.
Any ideas?