This is a 3 Mark II (B2) Suitcase Transceiver. It was developed by the British for clandestine use in Occupied Europe. Sets were issued to agents of the Special Operations Executive. I obtained this set from a collector, he had obtained it from a former SOE wireless operator who had used it in Yugoslavia.
I have an interest in clandestine operations in WWII because my uncle, whilst and Englishman, was assigned to the Royal Norwegian Navy in WWII. He was posted to a Motor Torpedo Boat that was part of the "Shetland Bus" operation, the joint Navy/SOE protect supporting the Norwegian Resistance.