Hi Martin,
If you have left R209 as it was modded then the chances are that it will still be set to 100K which is virtually the value chosen for extra torque in the cutting lathe application. see above notes.
In my analysis we need less capacitance delay for a heavier platter, hence removal of the extra 0.47uF would have made a difference.

However I have compared more closely block diagram and the circuit diagram, and there is most certainly a difference. The resistors are connected up differently.
The problem is that both variations could possibly be valid.
Also C210 on the PCB is designated C120 on the track side.
I am in the process of tracing out the actual track circuit on the PCB to see which is the correct version and will translate this to the block diagram.