It's pretty undoable to replace all capacitors. That's a huge amount on different boards. Probably unnecessary also. Trimmers dito. Due to the tolerance of the caps it will be needed to readjust some boards, which I doubt your technician is able to do, like adjusting bias etc on the tape board section.

Things that will need attention will the power supply boards( the bigger caps can leak sometimes, not always), amplifierboard (with a new relais), socket board, decoder board cd-player, upc board with it's few caps/backup battery, tapedeck with new belts, glass panels with a thorough cleaning (be very careful with the paint on the panels when you clean then for refitting them with new tape, new belts for the doors and probably overhaul for both motors with internal oxidized contacts (less torque). The cords for the doors should be cleaned or replaced. This last few things just only to achieve a smooth movement of the doors. Make sure these are aligned nice and properly when the panels are removed and put back again.

Only this above mentioned list of things can easily take almost a day of labour for an experienced technician. 

Thank you for taking the time to educate me on this.  Thank you for the detailed response.

I really appreciate it.

Beobuddy,

If you were sending off your 9500 what would you ask the tech to do?

THanks