I woud certainly put it in there to try.
And buy the proper one before you close the case.
Without that resistor, with the same bias setting, bias current in the output stage is higher.
That could have blown the output stage.
Don't worry about the supply voltages being lower.
They depend on mains power fluctuations.
!!! Lower that bias all the way BEFORE you put the power transistors in !!!
!!! Leave it on low while testing the amp !!!
Adjust after you have replaced the resistor with the original one.
Leo..