I got curious about the relationship with Gretsch the guitar and drum brand.
Found this info
here and
here (paraphrased): Friedrich Gretsch started the "Fred Gretsch Manufacturing company" making drums, banjos, etc. in Brooklyn in 1883. He died in 1895 and his son Fred took over. He began importing instruments some time after 1900. His brother Walter Gretsch joined the company also some time shortly after 1900. In 1924, Walter Gretsch left the company and formed the importing company "Gretsch & Brenner", which was apparently in business until the mid 1950's. Fred Gretsch's business starting manufacturing guitars in the 1930's with the familiar Gretsch name.
Doesn't help with your bass ID, sorry, but interesting nonetheless. Post some pics of your bass, so that people can take some guesses. Being that it's not actually made by G & B, it could be anything....