Unknown Ribbon Microphone
This unusual microphone dates to the early 1930's, but it is not clear by whom it was made.  The only place I have been able to find it listed is in a 1933 catalog issued by the American Sales Company of New York, a distributor of radios, parts, electrical appliances, etc., as seen below.  It is possible that it was made by the American Microphone Company of Los Angeles, but it is more likely that some other company made it, and it was sold under the distributor's name, as were many other items in this catalog.

It is a small microphone, almost cubical, about 3 inches on a side.  It is a very early ribbon unit, contemporary with the earliest RCA designs, and it may very well have infringed on the RCA patents.  It was also a very expensive microphone.  The high price, and possible legal problems with RCA could very well have doomed this unit to a very short life in the marketplace.

Sadly, a previous owner had discarded the original contents, and installed a cheap crystal element inside.

I would appreciate an email from anyone who can provide any more information about this microphone or, better yet, sell me a complete unit!