Enlarged firing pin holes in double barrel shotgun. Anyone hear of removing and replacing firing pin bushings?

Seriously??

Hallowell and Company has a description of it with pictures:

http://www.hallowellco.com/bushed_firing_pins.htm

The book on making double rifles on shotgun actions also describes doing it, I believe.

JJ Perodeau at Champlin Arms might offer this service.

Hope this helps,
Steve