Can't find any info on dates of production. However, on a specific gun, you can tell when it was made from the date code on the barrel flats. Either a Roman numeral if it's an older gun (I = 1945; count forward from there) or two letters, starting with AA in 1975.

Blue Book says the Condor should be worth mid-$6K range, the other two mid-$9K range, in 98% condition. I've only seen a couple Condors on dealers' lists, and from their prices it looks as if the Blue Book may be high on these guns.