I have a copy of the shipping records for the earliest 22/40's (K-22 2nd Model). The first 22/40 is 682420. It shipped---March 3, 1940. The second one, 682421, interestingly enough is blank-----likely would letter as "Open on the books"---translates to "We know we made it, but have no clue as to what happened to it." Also interesting/weird is some shipped to a Paul S(?) Linforth(?) in San Francisco----who is clearly someone who knew someone. He got 682424 & 682425, (along with a few others) shipped January 25, 1940---which looks like the earliest shipping date.
The last one I had is 682435, and is one of those once in a lifetime finds-------lettered as shipped "March 21, 1940, and delivered to Mr. Philip B. Sharpe"--------"on an advertising account at no charge to Mr. Sharpe." "This is a very important revolver." That's true enough, but I'd like to have stumbled upon one of the first ones they gave him---Registered Magnum #2. That would probably letter as a "very, very important revolver." Oh well!
Ralph Tremaine