OK, I stopped by Ames R&P today and found the following Glock armorer's business card on the bulletin board at the club.
THIS IS NOT A RECOMMENDATION. I don't know this person, I'm just passing along the info on his card.
Patrick M. O'Malley, Factory Certified Armorer, 34 Cabot Street, Brockton, MA 02302, 508-427-6557, cell: 774-259-1574
If you go to Brockton, make sure you are "locked and loaded", it is one very nasty city (even though there are some very nice homes there)!