That description could be any of about 1000 airguns, they all pretty much look like that. Is it a Winchester branded gun? There must be a name and model number on it, Winchester will be printed in large letters across the top of the gun. If it is a Winchester gun, there will be a date of manufacture on it, on the side of the compression tube above the trigger, stamped in very tiny numbers. Winchester sold a line of rifles and pistols in the 60s and 70s, maybe 8 or 10 different models, all made in Germany by Diana.