I just replaced the two pitch adjuster pots (already had done the two switches) and then went on to replace the 8 electrolytic caps on the motor control board. I'd already done the caps on the PSU board.
The pitch pots were easy to change as the mounting bracket unscrewed to give good access.
The 8 motor control board caps were more tricky. The first 4 were fairly easier to access. The four 4.7uF ones were pretty crowded in and 3 of them had leads off the bottom going to the motor unit. Still care and patience plus the odd hand from my daughter to hold the board for me and all are replaced and it's working very well.
The audible pitch on tricky music (e.g. piano where notes trail out) is more consistent / really first rate now.
It was well worth doing and cost less then £10 for the components all up.
Pic of new switches and old pitch pots
Pic after changing the pitch pots
Pic of a mates PL-71 that uses 3 switches instead of 2 as per mine and the service manual!
Pic after changing the caps on the motor control board
Pic of before caps were changed