It looks like Burt did not measure molds in MM but in Micrometers. I have no idea the comparison rate. There are no records of Hot Stamped chips. Find an inlayed one and there could be a record depending on the year.

I have no idea whether, either of, your chips were used at Harveys or not.
If one was, the other could have been. They could be generic chips. Who could ever prove it?
Here is my guess.
Chips were made on the Old Gem mold until it wore out. When the New Gem mold was made, it was bigger, to conform to the 39MM size.