1911 Springfield. I had a Millet front and rear sights put on 12 years ago. The smith milled the top of the slide to make it flat for the sight. A couple of weeks ago the stud cracked and the sight came off. Millet doesn't make them any more. Brownells had some and I bought 2. My new gunsmith installed one and after 50 rounds it cracked and came off. Now I'm thinking of silver soldering the other one. I've never silver soldered. Any recommendations? I cant switch mfgs as the rear sight is a Millet and the slide is milled.