That one held better than the one in the other channel. Throw the bad one away not to get mixed with good ones.
Now I'm enjoying your work Salas, but I will measure tomorrow for sure.
REC button on your Brymen DMM is MIN/MAX function. If already hooked up to measure voltage and REC is activated, when you power on it captures instant MAX voltage.
It shows that the drifted FT-1 unit wasn't grilled by turn on peaks because of its 200V spec.
...Also measured correctly biased. 165V point noted on the schematic, 162V in your build. Within 2%. Very close when considering there are differences in tubes bias details between samples or alternative types.
In any case, better using 250V or higher for C3 & C4 when possible. Especially so for C6. For peace of mind.
I can't get reasonable priced 250V teflon caps for RIAA but at least my peace of mind is guaranted using C6 3.9uF Mundorf Silver Gold Oil rated 1000V.....
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After some months check again if the C3 values remain correct since there's been a negative capacitance drift incident with an FT-1 in one channel. Maybe it was simply random, maybe there is a tendency.
With 7N7 in the output stage and those modified resistor values around it, Ip should be closer to 9mA and C6 voltage bias 170-175V.