Thanks Spanky. Can I borrow yours?

Or can you scan that part for us? It would be a big help.
And about the switch to tubeless, I am getting conflicting reports -- one source, who has access to a vast library of old truck literature, is telling me GM went tubeless in '55, with tubed tires being optional (and preferred). You guys are telling me '56. Can somebody cite a specific reference for me to settle it?
We'll get this sorted out. But this rabbit hole goes pretty deep!
Thanks,
John