OK so update. There are two speakers but the other one not pictured has a totally rotten woofer. The cone is all but gone, i can only assume the coil is shot but the basket and the magnet look original so maybe someone can fix it.
You were correct about the serial number it is HD BB and there is an R in the number see below.
I am going to pass on this set. They had the one playing and I am not sure i heard any noise coming from the tweeter but it was hard to tell with background noise and the signal coming from a fuzzy radio...
The auction is in Ithaca NY incase anyone else is interested and close by.