ipd seems to have a good selection
ipdusa.com
Also less specific parts fcpgroton.com is a good resource
Europartsdirect.com is also a great source for '89 240. Sometimes cheaper than IPDUSA.
Yes I believe actually the 1986 to 1992 Volvo 240 4 doors are all interchangeable parts but I'm not sure for 1985 and earlier models.
If they're identical, yes. Try it and find out.
at a junkyard
try this web site ive bought hard to find parts there. http://www.vlvworld.com/indexframe.html
Haynes has a good one
long answer: yes
ebay, salvage yards, craigslist, local used foreign/volvo shops
Yes the 240 does have fuses. Was that your ?.
how do adjust timing belt on a volvo 240 DL ?
how do you reset engine light on 1991 volvo 240
There is a sticker on the core support that has it. Or, Haynes manual