hello,,have you tried gunparts in ny for the site and pin,,sound like a fireing pin problem with the nylon 12 and the site should'd be hard to find for a 69a ,,there both collectable rifles and the 69a is worth between 300-450 and the md 12 should bring around the same numbers,,heres a link for gunparts this one is the 69a parts
http://www.e-gunparts.com/products.asp?
chrMasterModel=0950z69A&MC= and this one is the remington 12
http://www.e-gunparts.com/products.asp?
chrMasterModel=0860zNYLON%2012&MC=,,if they can't help you let us know and i can post some other options ,,
bigcurt