Larry Clinton At Frankfort, (Central) Indiana
Lee has it correct. I have repaired several - I use a similar method to Lee's. I use my Dremel with a drum sander wheel to clean the hole and tenon, then wrap plane shavings around the tenon using either hot hide glue or liquid hide glue until it is oversize then either rasp or sand it down to a tight fit and glue it in with hide glue. I don't have a level enough shop floor, so I set the chair on my saw table to make sure it is lever while I clamp it tight. The great thing about hide glue is that it will stick to itself years later, making future repairs even easier.