Translation system receiver - Tesla?

This four channel wireless translation system receiver is unknown production, perhaps Tesla. It works on LW loop principle, 4 channel separated by a frequency. There are two Tesla Ge transistors and one Ge diode involved, the concept of the receiver is a 1V1 (RF preamp, detector, AF amp). Powered by one 1,5V cell. Unfortunately, the headphones connector was ripped out, thus, cannot be restored to the original state. I guess the begin of sixties as a production date.
All photos are © OK1UHU, 2013