It might be the wiring... You mentioned having had it working perfectly, before rewiring it.
You do have the wiring away from the parts in the oscillator circuit sections, but the wires to the Pitch and Volume Trim-controls are parts of the first and fourth oscillator circuit sections. Them having longer lengths and being bundled with other wires is probably one trouble.
Use this image as a reference for the wiring: http://www.paia.com/manuals/docs/PTphot ... Repair.JPG
Yes, the CDSH270 diodes are preferred. They give a bit more output for the pitch and volume heterodyne signals.
Using 100pFs at Cs 39 44 and 37, and, adding a 6800ohm on R81-3 to R81-2 provides better waveforms at the Timbre control extremes and improved volume hand-to-antenna response.
Bundling the wiring can increase the tendency for a feedback condition to occur. Adding a 0.1uf to the bottom of the board at solders for the Q6 collector to a nearby ground helps prevent this, but it isn't so likely to occur when wires aren't tightly grouped (and, the audio output level control advanced beyond about 3:00). There's plenty of f-v circuit section pulsing energy and not so much audio signal energy and when things are wide open through the VCA section, it all gets mixed-up.
About the Vol Trim, Velocity, and Pitch CV controls not affecting anything, these probably aren't indicative of the troubles you've encountered. With the volume pair tuned for traditional control response, the Vol Trim doesn't work to change the volume as much as it did for the originally prescribed controller response; however, if you'll set the vol trim about midway and stop with the adjustment of L3 with the background 'pitch' just at the brink of audio/post-audio, you should find that the vol trim works to fine tune the volume about this audio/post-audio region. It's when the pair is tuned just post-audio that the volume cv will be greatest and optimized.
Velocity works to vary the amount of velocity cv that goes to the velocity cv output jack, and, to the VCA section to distort the smooth sounding wave at the ccw Timbre control extreme when the hand to volume antenna control is rapid. The Volume CV control only works to vary the amount of volume cv at the volume cv output connector.
The only difference between the C and D versions of the circuit board are the holes for the i.f. transformers at Ls 1-4. They're not so tight and greatly reduce stress on the legs as the part is inserted making it less likely the wires break off the top of the legs inside the part.
Here's to success!