Looks like a lot of thought went into this design. I feel flattered - he uses my "cardioid only" relay system first introduced in the KHE, and the term "reedy" for which I was ridiculed twenty years ago.
But the proof is of course in the pudding:
"West German M7" - what is that supposed to be? With its green tape it looks to me like a Thiersch M7. If so, no chance for this thing to sound any good: regardless the sophistication of the rest of the design, everything rises and falls with the capsule- THE bottleneck in any condenser mic. But hopefully I am mistaken, and there is a new shop in West Berlin making PVC capsules?
Another mystery: what tube? The photo shows something that looks like a solid state tube emulation?