This item has been sold, retained here for reference only.
never used, age unknown, well over 30 years old.
Label inside says (besides all the patent numbers):
"Gibbs Manufacturing & Research Corporation, Janesville, Wisconsin
Subsidiary of Hammond Organ Company, Made in U.S.A.
Notice: - Purchase of this device does not conver a right to make, use or sell the system covered by U.S. patent # . . ."
Patent Canada 1963"
Under the 6709 is # 1122 stamped into the metal,
and on the end is # 34, in black ink, with a square around it.
I think I purchased these from Surplus Electronics on Hackensack Street in Carlstadt, NJ,
sometime in the 1970's. Surplus Electronics was located in the former Carlstadt Post Office building.