Investment in 96’s 850’s? Ideas for cruise control?

Hello together A while ago, the official Volvowekstätte advised me not to even make an oil change and to look for replacement. Too big are the necessary investments. Since then, I have also travelled over in the V70III Forum and look around. But the 850 was a super car so far and I would like to follow this track further. I have already successfully treated the licking steering gear (ev only temporarily?) with LecWec. Now I was with an independent Specialists for older Volvos. I would have to expect about 2500 Euros (in Switzerland) to prepare him for the test. Also included would be the change of timing belts, WaPu (the old one is over 10j old) and a flushing of the machine. What do you mean? Is this worth for a twenty-year car (850 Kombi with 20V gasoline) with 330 Tkm? I have to say that I don’t drive 10Tkm a year anymore. So there won’t be too many of them over the next few years. As before, he would also have to take part in long holiday trips reliably. And then something else: the cruise control only works sporadically. When it goes, the control via the buttons in the turn signal lever works without any problems. But usually nothing happens if you want to use it. There is no difference according to outside temperature. I have tried to adjust the pedal switches already. So Zpfen joined pedal pulled out. No effect. (Which of the two switches is Do you have any ideas what it might be? I miss this part hard on long rides? Thank you for your help! Gruss Bno