PHILCO Metal Sign

We purchased this metal Philco sign for $15.00 and are very interested in knowing a little more about it. It is heavy, made entirely out of metal and glass. The sign measures 4 feet wide, 9.5 inches high, and 6.5 inches deep (front to back) and reads "PHILCO a musical instrument of quality." The PHILCO letters are glass, the front is gold, and is framed by a metal design that looks deco. We know that the Philco company started selling radios in the late 1920's early 1930's, but we can't really tell what it was used for (it is slanted which doesn't make us think it was used over a doorway). It is designed to be lit from behind by 2 light bulbs, the fixtures and everything are all original too.

Thank you so much for any information regarding it's history/value.