Well, the audio board miiiiiiiight be a U87A clone type deal, possibly? Since the transformer is a 12:1, it shouldn't need that second transistor as an emitter follower for low-impedance drive, so that might be a capacitance multiplier?
The "PSU" board is more interesting though. The pair of inductors and capacitors near the bottom edge must be between the transformer secondary and the XLR output. Otherwise, it kinda-sorta looks like a Schoeps-type oscillator, but i'm only seeing ONE inductor, instead of the usual two
That being said, manual labor must be dirt-cheap in China - i wouldn't exactly call this "design(ed) for manufacture", with those dozens of wires flying all over the place...