Carl - I am pretty sure that plate was still attached to the inside of my Stuart, if not then loose with the spares ?
Also there was at least one very badly rusted example of that radio table as fitted to the early M3 with the spares, although I admit I was not certain exactly what it was for at the time.
The Museum Stuart still has the radio plate inside the hull, though some B%$#@&d had ripped the data plate out and stolen it many years ago.
I could try to photograph the plate some time but it's dark in there - and there are spiders...
Cheers
Phill