It is unlikely you will find a local web shop selling old Volvo parts. I recall the Bosch Motorsport local dealer did any Bosch part number, you will pay for the privilege though. The unfortunate reality is that most parts we buy come in from overseas. A couple of specialist workshops may have these in stock, I feel rather repetitive promoting them again, have a quick search through the site for their names.
There is the list here, though it is fairly broad: https://ozvolvo.org/d/420-420
Experiences vary, though there are generally four common websites for Volvo parts:
FCPeuro.com (USA)
gcp.se (Genuine Classic Parts - genuine Volvo - Loads of stock from Sweden)
ipdusa.com (USA)
Skandix.de (Germany - awesome range, massive shipping costs for small orders)
I would try the local workshops first.
