The integrator stage that is attached to U7 on the main board has a 5 kΩ resistor that is a carbon gold band grade radial.  I decided to replace it with a thin metal film resistor, for good measure, and raise the frequency cut of of the integrator while I was at it. I left the values the same for now and left it as a task for later.  I'll attach schematic when I get back to the lab.

Presently the circuit is as illustrated below: