I had the same experience on the drill bit thing, a broken drill bit in each side of the lug, the trigger guard wasn't coming off. I had used a temporary phillips head screw in the trigger plate that didn't show but it bugged the heck out of me.
I shaped all the wood on both the sides of the trigger guard with a tiny riffler file, a scraper and sandpaper, there was a lot of wood and it took me a while.
I guy on here said to buy a 1/16" carbide bit, put it in the hole in the stock and using only the weight of the drill let it eat. After about ten minutes of letting the drill bit eat I started seeing metal chips come out of the hole, 5 more minutes and I successfully drilled out the broken bits and opened the lug back up.
If you can find some 5/64 music wire it will be just right for your larger hole. Hobby shops sell it for RC airplane controls. Ace Hardware has it , some stores stock it or you might have to order it online and have a store pick up. You can get it on ebay but not in small batches like at hobby shops, more like 30, 36" pieces at a time.