On the CM-63 schematic, R6 is the same resistor as R10 on the CM-60 schematic and is 3k3 instead of 150 Ohms. That should fix the low voltage on the JFET circuit. And, for somewhat lower noise, the JFET can be replaced by a 2SK209-Y (mind the Y). I did not try that, though. But it should work. I bought the CM-60 and CM-63 just to serve as donor bodies and as a reference to compare my own PCBAs with. I did not intend to modify the stock PCBAs. Replacing the two resistors on the CM-63 was all I did.
Jan