I’ll have a look at the back of the switch. The one in my car is the older switch to the one in your pic.
I just found this on eBay:
https://www.ebay.co.uk/itm/Volvo-740...wAAOxy9eVRLTy0
Much of that does look similar to what’s in my car though. But, the vacuum hose is completely different. Mine is a rubber hose about an inch long that joins a T piece into another big rubber hose that runs along the bulkhead. I can’t see any of the electrical bits and bobs though, so I reckon someone had a go then ran out of interest/skill and didn’t fit much of the electrical stuff.
I don’t particularly plan on ever using the cruise though...