WS19 wiring diagram - schematic

[Patrick Johnson]

For some time now I've been pondering where the 19 set wiring diagram would have been mounted in Commonwealth M4A4 Sherman tanks. To date I have not uncovered any photographic evidence as to where they would be mounted within the turret interior, and furthermore, I have been advised from a knowledgeable source in England that a location for this wiring diagram could not be determined from a number of Sherman M4A4s "targets" he viewed on tank firing ranges in England. Since one of these plates came in every Sherman installation kit, until today my thought was that it was carried in the Satchel Signal Bag along with a set of headphones. Well, much to my surprise, a current ebay auction yields a possible answer. Pre-drilled mounting holes on each corner of the wiring diagram's plate appear to coincide perfectly with the holes in the mounting plate found welded to the top of the Transceiver case, see attached picture. Has anyone seen photographic evidence for this plate mounted in a similar fashion?
I have an original wiring diagram plate and will be able to test it out on my 19 set this weekend; hopefully another mystery solved! Now I'm curious to see if the wiring diagram can only mount in one direction as pictured, or can the plate be successfully mounted when rotated 90-degrees?
Cheers, Patrick