[old_tv_nut]

In tube gear, a large part of tolerance budget has to be allotted to tube variation; then the stage should be designed with enough head room to absorb that plus a specified resistor tolerance. Stages with higher signal level will have less headroom for tube variation. In the case of video output stages, the tube is typically running wide open at max contrast setting, and therefore there is relatively great variation from tube to tube and less room for resistor tolerances while keeping signal excursions within limits.

Then there are circuits in which fixed resistors set a limit on adjustment range and touchiness of things like V hold, height, and linearity.

Based on that, without a sensitivity analysis of each stage, I would replace resistors that are out of the manufacturers spec, just because I don't know how close the designers cut it and it will help avoid problems when tubes are replaced.