Just a post to confirm another number on a tag. I bought a ‘53 that had been caught in a brush fire. The tag was burned like the rest of the truck but the tag, with rivets, clearly has another number. This number correlated to a rebuilt engine tag (the block was not stamped on the pad by the distributor). The rebuilder was a company called Mustang I believe but I could not find a picture of that tag. No information came with the truck other than they had purchased it locally many years prior to the fire.
https://www.flickr.com/photos/advance-design_parts_co/8130562112/in/album-72157631870734114/