I have some experience with them,
they are very fine to service.
upstair there are 3 sub chassis, sitting in sockets, plugs. From right to left they are:
PSU, second IF, Audio stage with subchassis in the sub chassis what is the BFO,
When they are removed the rest is much more easy to turn and to handle. The idea from Telefunken was, in the service to swap complete sub chassis and repair them in the factory.
The real problem with this radio is the temperatur stabilisator... the old EE made it with (Gussteile), parts from thickness boiled steel, so it is so much heavy. The complete Tuner part have no sheet metal, thats all made in the kitchen with fire + sand