[G6Tanuki]

Sympathetic capacitor- and where-necessary resistor-replacement too is sensible.

In particular the screen-bypass capacitors and their associated resistors. The resistors often drift high by up to 50% and if the decoupling capacitors are also leaky they can pull the screen-voltage down significantly causing loss-of-gain.

AGC-line decouplers (both R and C) are also candidates for attention: though the voltages are relatively low, any increased resistance or capacitor-leakage can cause overloading of some stages because the full AGC doesn't get to where it's needed.

There's also a couple of decouplers associated with the VFO and the BFO: when these become aged the continuous slight variation in leakage causes 'scintillation' - random relatively rapid wobbles or wandering of the BFO/VFO that can really spoil the pleasure of using the radio.

I also once 'fixed' a WS19 that had a significant frequency-drift issue by replacing one of the under-chassis coax interconnects. The braid had suffered the dreaded 'green' corrosion under the outer jacket.