strayhorse, I went back through my 1960 and 1961 "American Rifleman" magazines and have the information you requested:
The only company that seemed to handle the guns like your Dad's was Klein's Sporting Goods in Chicago. Of course at that time you could mail order handguns with virtually no restrictions and have the gun sent directly to you (we called it freedom back then).
The July 1960 issue has the first mention I saw--a small segment of Klein's larger ad on page 3. Has a tiny picture of the gun.
August(p. 61), September(p. 7) and October (p. 4) have the best ads for those guns, a picture, mention of availability in both .22 and .22 Magnum, and saying that both guns with 'original' blue are available for $39.88 or "deluxe" refinished guns at $44.98.
November(p.5) and January 1961(pages 2-3) drops the offer for "deluxe" guns.
April 1961 (p. 10) has a slightly different ad saying that the barrels were new, Belgian-made. This was the last ad I saw for these guns.
If I had a spare copy of any of the above mags I would send it to you, but I don't. However, as I mentioned before, copies are neither hard to find nor expensive to buy. I'm sure eBay has them for sale from time to time (often you can buy a whole year, or at least multiple issues, for about the same price a single copy will cost you). And there are other sources.
Regards, Ralph Boineau