Not to practice necromancy reviving an old thread, but Salinas, CA PD was carrying Model 59s in about 1974. When I was at the academy in 1975, their guys all had 59s. I bought one as an off-duty piece after firing theirs. Bellevue, WA carried Model 59s not much longer after that. When I got there in 1981, they had had them for several years. They were the first agency in Washington state to carry autoloaders.

The first S&W 9mm I ever saw (or shot) was my cousin's steel frame early model 39. That was in the 1960''s when I was a kid. He was a US Postal Inspector, and carried it as his off duty "in the vehicle glove box weapon."