I have a couple of the 60's vintage Redfields that were mounted on Model 70 Winchesters. At the time, they were one of the better scopes. The rangefinder did work as did the Accutrac system if you could see the numbers in the little glass window. Back then, a 500 yard kill was a rare event ,unless you were Elmer Keith.
About 5 years ago Remington produced a limited run of Vietnam era M-40 Sniper Rifles for the Scout Sniper Association. These reproductions picked up the serial range, were parkerized, were fitted with an ADL oiled stock and machined for a stripper clip. Since many of the originals were fitted with 3x9 Redfields, prices for excellent condition samples were driven as high as $700. An original off of an original rifle could fetch $2000. The Military painted the scopes green and used Redfield mounts. The rangefinder in the Redfield worked perfectly to 600 yards when lined up with a man's shoulders and waist. I have one of these rigs and was quite surprised when it consistantly produced 2.5" groups at the 500 yard line with Federal 168 Match ammo.