While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
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Now that one will likely be a toughy. You may need to look at finding someone to fix this one or make a new one for you. It's not a complex part so it shouldn't be TOO costly. But even at that a regular gunsmith may need to charge more than you're willing to put into the gun. Either sell it off as a project gun or find someone that does some home shop machine work that'll do it for less than what a commercial smith or machine shop would charge.