Hi Bill,
I remember these ads well. I wanted one in the worst way, but being newly married and our first child on the way, $190 may as well have been $190,000.
I do remember reading that JFK owned one and would take it out to sea on his yacht and sink 55 gallon metal drums with it. He also carried one of the earliest AR-15/M-16 rifles on board. I think he was also a life member of the NRA.
One can't help but to wonder how the Secret Service felt about being out-gunned by the guy they were supposed to be protecting?
About 15 years later, I did score a nice 20mm Lahti complete with all accessories and wooden shipping case for the astronomical price of $200.