The earliest I find it, although I recall the Citizen's Model in earlier ones, is 1939:
32 heiser 1939 (12).jpg
The plain-headed steel rivets and football maker's mark fit that time frame. The former began w/ WWII we believe, the mark boes back to the 1920s and was still being used when Heiser ended in 1968; nevertheless the model wasn't made after the War that I can see, at which time it was under new ownership -- twice until, well, technically today (because Keyston Bros. still existed when last I looked; NV.
Turnerriver will know more as being the Heiser specialist amongst holstorians. Me, I'm more of an 'origin of species' type vs. a brand but if I had to pick one, likely Bianchi Holster because I once worked for them.
HH Heiser Gun Show Find
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