Today I was starting measurements of the North TTFSS, when I noticed that the 100Ω metal film feedback resistor on the Common Path was bent (R3 on the TTFSS Common Path schematic). When I touched it further, the pad it was soldered to came out. I believe this is the cause of awade's poor measurements of the North TTFSS this weekend.
I repaired the North TTFSS by soldering a 100Ω black surface mount resistor that was taped inside the box into the feedback resistor spot, and connecting everything with a hunk of solder. Not the best practice, but it works even though the pad and trace from R5 to R3 is gone.