I actually bought them with a bunch of other stuff when the GMC house sold out back in the 60's. Back in those days the GMC house installed a lot of short blocks and stamped the rest of the numbers on the distributor boss because thats how the vehicles were titled in Texas in the early 50's. The wooden boxes don't say GMC, but they stamp narrower than the Chinese numbers you get now. I even have one more blank ID tag that came with the stuff. I bought a repop on eBay recently, but it is noticeably different than the real one. I think probably any numbering set that is 50 years old would look more like the original.