There is a person who makes stained glass objects in the Washington Street Artists' Gallery. She may be able to do the repair. I have seen her book and photos of other work and she does make custom windows. I cannot recall her name. However, if you stopped in there, someone on the staff should be able to give you here contact information. The Gallery is open Friday - Sunday noon to 5:00. It is on Washington St, the main drag in Charlestown and down on the block near Grandma's diner and across from the jewelry store and antique light shop.
“I know up on the top you are seeing great sights, but down at the bottom we, too, should have rights. "Yertle the Turtle and Other Stories"” by Dr. Seuss