I tried many times to get more info Franz and Fransch, so far no success.
Fransch was in Woodside according to the pickup stamp and Franz in Astoria, according to Gilbert Diaz (see Hans book). Now both areas are in Queens and border to each other, so both are possibilities that it was one and the same company or two companies just in the same general neighborhood.
And yes, the Fransch Electric Company was most probably owned by Frank Schultz, the theory came from this great post of Ed Sharpe:
could a few guys here maybe measure the dc resistance. I did find a winder that rewound a dead franz pickup a while back. I think he would be willing to recreate that pickup if we can get some measurements. his website stated that it was very strong and bright though I think the strong part...
letstalkguild.com
And that means Franz Schultz and Charles F. Schultz were most probably relatives.
I tried via friends who live in Sunnyside, just South of Astoria and Woodside, to get info from the libraries in Woodside and the central library in Jamaica/Queens but was not succesful in getting any info about any or both companies at all. Like they never existed... One would need old Queens phonebooks from Woodside and Astoria from lets say 1953-1958 timeframe.
The Franz and the Fransch look similar inside but still different to question the same factory.
Ralf