I would think the radio control head was made to fit in a dash opening. If the chassis has a socket for a vibrator, that will help with the year information. Sometime, I am guessing in the mid thirties, they came out with the vibrator. Before that they used something that was like a motor generator set. Usually on these old radios, you can replace the speaker with a modern day permanent magnet unit. This radio would have used an electro-dynamic speaker. I just finished rebuilding my 1938 Chev radio and it works just fine with a modern speaker.
Ray Holland over on the VCCA site may be able to shed some light on your radio. I can get his Email address if you would like.
