Hi:
I first used a "Lewis" when I entered L.E. in 1962.
I observed them in the 1950s in my home town used by the city P.D.
Later I found the "Lewis was very popular with LAPD in the 1940s and 1950s.
Now with this post the Lewis (with the FBI Agent M&P 2")was around in the 1930s.
Great holster.
Jimmy