Wore out three sets of tires already!
Good question WillWork,I'm also kind of curious if you've found any stamps on the inside of your Overdrive brake arm??
I think all I've come up with so far is a couple of "H 8" and one "A 8" believed to have been off of 68 Mini Twins. None of the earlier kickback hubs I've had were marked at all on the inside of the arms.
I’ve seen the date codes on the back of later year Overdrive hub brake arms. They seem to be on the “Model B” such as the above ‘68.
I have 4 1965 Stingrays with the Blue Band Overdrive and they do not have date codes on the back of that arm.