Electrical function delete!
I did the same on my hatch lock when the motor failed. I now use the key.
volvolugnut

Google yielded an immediate result: https://www.swedishcarparts.com/parts/1604-volvo-interior-door-knob-trim-ring-s60-s80-xc70-xc90-v70-sand-beige-39978892 They ship free to the states, I actually need two of these for the wife's car. I can pick up at my mailbox if you want me to forward it to you....

So my choices are to leave as it is now, unhappy wife, or fit the 07 units with the blue caps not the grey.

There is no choice here , really, only the illusion of choice.

Send us a picture of the blue caps when done