Most if not all of the 'technical' parts are available, either original or aftermarket. You'd have to look a bit further for interior parts and trim.
VP
http://www.vp-autoparts.com/index_staff.htm and CVI
http://www.cvi-automotive.se/en/arti...40-73--240-b20 in Sweden both sell original parts. I believe VP took over all Volvo's classic stock, molds and patterns and even sells interiors.
That was misbelieve, GCP took over Volvo stock etc, so there you can find all you need for your concours 144:
http://global.gcp.se/ GCP also has exploded diagrams for ALL parts online, excellent.