I don't think that's a radio, just an antenna amplifier. I'm not seeing where demodulation would happen. Some values seem kinda weird to me, like R4 on top of the cascode seems sorta high for something that oughta have a lot of bandwidth (and the way L2+C6 are drawn is odd). Likewise 390k on the emitter of Tr3, seems like very little room for bias for something that's supposed to drive 50 ohms. Bandwidth at the input looks to be <2 MHz, so maybe it's meant for AM broadcast or 160m.
R4 controls the output impedance of TR1. It'd have to be high to keep the loaded Q of the L2 tank high. R10 looks like a mistake to me. Probably should be 390 ohms.
Agree with your assertions though.
It might have been reverse engineered from something badly or drawn up by someone smoking crack. Even Tektronix had that problem on occasions in their service manuals ...
