Dad has a Marlin 81 DL. He got it in the 40's so it is a heirloom. He traded a pair of iceskates and his Red Ryder for it. He has since lost the aperture sight for it. I have put on a open buckhrn sight in the dovetail cut in the barrel but I sure would like to find a replacement peep siught. Numrich doesn't have any. Any ideas?