A friend of mine recently came up with this shirt.  Through some research, he believes that it could be from the 1967 USGP @ Watkins Glen, though that is just a guess.  The names that can be identified are:

• Graham Hill
• Dan Gurney
• Denny Hulme
• Mike Spence
• Jim Clark
• Michael Parkes
• ?
• ?
• ?

The question for you, is: Who else autographed this shirt?  Can anybody confirm which race it was from?