Slowly going down the rabbit hole with stock certificates. Plucked this one off of eBay after a tip from @Buster- 5 shares of Converse purchased in 1926, signed by the company founder, Marquis Mills Converse.

And this was the same year Chuck Taylor became the player manager of the Converse Allstars basketball team (4 years after the show debuted).

Pretty cool slice of random hoops head history!