Updated by Larry Bunce, who maintains the organ.
I worked on this instrument c. 1975 as an employee of the Berghaus ORGAN Co. One clue as to the builder was a shipping label inside the case that said it was shipped from Boston via American Express. I would presume that it was built by an organ supply house and installed by a local tuner/repairman.
A clever adaptation made when an electric blower was added was that the blower switch was operated from the drawstop labeled "Bellows Signal."
Builder's Nameplate: attr. Emil Witzman
Status Note: There 1984.
Renovated Berghaus Organ Co. 1982.