Music Master Tube

The tube shown here was sold under the Music Master name, and probably dates to the mid 1920's.  Music Master was a major manufacturer of phonograph horns, and radio horn speakers.  To a lesser extent, they made radios, and apparently sold tubes under their own name.  Exactly who made this tube, and what it was used in is unknown.

The base is a standard short-pin UV-199 type base.  But, the tube is not a UV-199 equivalent, as the filament voltage is different.  This tube was designed to operate on 2.0 volts (the 199 was 3.0 volts), and the filament drew 0.08 amps.  The tube is about 2 3/4 inches long, and it is about 1 1/8 inch in diameter.

Stamped into the base is the word "Germany", which almost obliterates the logo of the Shaw company, which was a US company.  Horizontally oriented elements were very common in European tubes, but not so in the US.  Was this tube actually made in Germany?  Or, was this a US-made tube, but they wanted the buyer to think it was imported?  Or, was this just an attempt to avoid paying patent royalties to RCA?

I would appreciate an email from anyone who knows anything about this tube!