I couldn't find the listing on Gun Broker. I have a BL 4 20 gauge that the reciever has a purpleish hew to it. I think it's a mid 70s manufactured gun. I did not buy this gun new but I feel certain this was original because the gun is still in like new condition. I never minded the color difference, and the gun shoots and handles great for me.
If you have a bad feeling about this guy then by all means stay away. I certainly wouldn't buy a used gun with a no return policy. What if it has a major problem?