Keymonica Harmonica

This harmonica was made by Proll Toys, Inc. in Newark, New Jersey, after 1947. It is a Keymonica model. This harmonica has a white plastic body with a white plastic mouth piece, and 10 multi-colored plastic buttons. Cast on the harmonica:

KEYMONICA
PROLL TOYS INC.
NEWARK, N.J.
MADE IN U.S.A.
PAT. NOS.
2416451 – 2407312
2373129
OTHER PATS.PEND.

This harmonica features the following patents.:

U.S. Patent No. 2373129 dated April 10, 1945, for the construction of harmonica reed plates and reeds, by Finn H. Magnus of West Caldwell, New Jersey.

U. S. Patent #2407312, dated September 10, 1946, for harmonicas in which the reeds or reed plate, or both the reeds and reed plate are formed of a plastic composition by Finn H. Magnus assignor to International Plastic Harmonica Corporation.

U. S. Patent #2416451, date February 25, 1947, for a method of and making integral reed plates and reeds by Finn H. Magnus assignor to International Plastic Harmonica Corporation.