Manufactured from 1975 to 6/80, Defiant I has a one piece fireback; Defiant 1A is a Defiant I converted to a two piece fireback, sides wrap around the front; Defiant IAI is a I or IA converted to a two piece fireback and two piece baffle, sides wrap around the front.
Available parts for the Defiant I , IA , IAI , 0019 and 0028 are listed below.

Identifying your Vermont Castings Defiant

Vermont Castings Defiant 1A Parts List

The History of the Defiant