OK... I have had this Ultra Lux for maybe 20 years. I took the rear sight off when I had a scope bell causing an issue touching it and opted to remove the sight rather than go with a smaller diameter scope. Now, years later I take the rings and scope off and attempted to put the ramp sight back on. All goes well except its very loose and will wriggle off. I thought I kept all parts, but possibly there is some sort of spring steel device to keep the rear sight snug or what?? I cannot imagine me losing some part, but who knows. I am open to all suggestions. Thanks you guys and gals with a solution for me..!!