Huge Rare Vintage circa 1932 Ribbon /Tube Microphone PB-17 type For Sale

Offered here for your pleasure is this incredibly big and extremely interesting old ribbon/tube microphone. I have done some research on this mic and asked some knowledgeable people about it, but have not yet been able to positively identify it. What I do know is that this is likely the first ever tube / ribbon microphone.
Take a look at the pictures and compare design elements of the ribbon motor assembly and electromagnet structure of this mic, how they seem to closely match the July, 1932 Marconi and Harry Olson patent drawing that can be viewed in its entirety at the super excellent Xaudia vintage microphone blog at first thought that this mic may possibly be a rare example of a RCA PB-17,but after my research I am no longer sure of its origin. The microphone in this sale uses two unknown tubes, whereas the PB-17 uses three vacuum tubes. The body dimensions are different from the PB-17. The RCA PB-17 is one of the scarcest microphones in the world, with just a few known examples in existence in private collections. The microphone being saleed here may or may not be related to RCA or to the PB-17, I really just don\'t know for sure.
My thoughts lean toward this mic possibly being a rare early RCA prototype.
The microphone body tube is aluminum. The Connector end of the mic is made of cast and machined aluminum, the bell of the mic is cast aluminum.
Asmall rectangular perforated piece from the top of theperforated metal head basket is missing (see pictures). The vacuum tubes are both missing. I don\'t have the external power supply, but someone knowledgable about such things could surely make one for you.
This is a microphone design that utilizes an electromagnet instead of permanent magnets, that is why there is a coil near the ribbon motor, to power the magnets. We can know this microphone was made sometime around or before 1932, because shortly after that powerful permanent magnets became more readily available and were used by RCA and other companies in their ribbon microphone designs.
Besides the electromagnet coil, there are two large transformers in the mic\'s tube preamp signal path. I have a feeling that this mic, after it has been brought back to life, will sound incredibly amazingly wonderfully cool. Don\'t miss out on this mic, you will probably never ever see another one of these for sale in your lifetime.
This microphone is untested and is being sold as-is, as shown in the pictures, to the highest buyer.If you have any questions about it or would like to send me your thoughts and comments, please feel free. I have added a lot of pictures for you to enjoy. If you have any questions, please ask them before offerding. Thanks!

---