I agree somewhat Allan.
Goodyear chip could have been made after the fact.
WCS did sell the mold.
Langworthy did sell the mold.
Burt did make the chips.
BUT:
USPC could very well have been the original manufacturer and transfered the mold to Burt in the 1947 buyout. That would date the mold to the 1930's or maybe late 20's.

Blanchard can only help so much with info due to the early 1950's fire at Burt.

Burt never hotstamped any chip. They had a strict policy against hot stamping chips.
All HS were put on by distributors of the chips.

Some history is just lost to us.