Apologies to all (inc FJJP) if I perpetuate this aspect, but I am now a little confused, 'Walter'
the aircraft only needed a hand held unit plugged into a radio headset socket to get accurate range (Mk1 or Mk2) or to get accurate range and approximate bearing (Mk2) the palletized, self contained unit that included the requisite antennas
If this is so, what would be the significance of the 'peculiar' code set on the aircraft SSR box to which you refer? Have I misunderstood your line of reasoning?