Aleene's 21709 Jewelry & Metal Glue, 0.7 oz - Instant Adhesive, Permanent Bond, Waterproof, Dries Clear, Ideal for Repairs

Since this is a scrapper, but you like it and seem to want to keep it (I have scrappers I keep for myself, so no judgement; just no one is likely going to trade you), I’d suggest you get some pin backs and glue off Amazon. I’ve had quite a few pins break over the years and this has been really helpful.