[rotorwrench]

Those old resistors have to heat up to drop the voltage. Through years and years of heating cycles the copper wire inside will crack. After cracking has happened, when it heats up further the wire will barely pass electro motive force and eventually it will open the circuit altogether. I would replace that resistor just for piece of mind if nothing else. Now who makes the best replacement out there, I can't answer.

Kerby