Initially, Turnbull did both the CC and carbona blue. USFA called it Armory Blue. The ovens USFA installed were both for Armory Blue and CC but USFA never got the CC process down. Also installed their own nickel tanks. Prior to that, nickel was done by either Baron Technology or another company in MA.
Regarding Turnbull guns, USFA would send them completed guns in the white with DT serial numbers. After awhile, Turnbull would get just the frame with TG and BS attached. He would get a selection of internal parts plus cylinders and barrels to make up guns as needed. These would also carry the DT seal numbers.