My uncle has a model 37 pump and there is a little ring on the top of the forend which is like a retainer.....when you cock the gun down the little retainer comes loose. If we hammer it down on the forend it stays temporarily but not for long because we have been through this many times.... we cannot find a new retainer for it so I am wondering if there is some kind of glue or something that will hold it on.......before anyone says we should take it to the gunsmith we just got back from the gunsmith and he said he will be way to busy to take in any more guns until after january. So what kind of glue could we use to glue this metal retainer to the forend?