Good memory, TD! That stamp kit was at the San Antonio Field Office. After ATF became a separate bureau the stamping was changed. The new numbers started with ATF and was followed with a 5 digit number that corresponded with the District Office that issued it. Houston District number would have been - ATF53100***. The stars signify the numeric sequence so each numbered firearm would not duplicate. In the mid ‘90’s, the Districts were changed to Divisions and the numbers again changed. Houston Division issued numbers looked like this - ATF745400***. Another change a couple of years after that looked like - ATF782000***. I don’t remember the exact dates of the changes. Hope this helps.