Well guys, I tried the ebay thing and didn't have any luck with breaking Volvos, BUT I did find a 1992 940 in silver, top end of my budget but it's a barn find that's been nicely brought back to life, so I've pulled the trigger, with the only caveats being that it's a 2.0 and 4 speed with overdrive...
Luckily I know a guy with a 2.3 motor and 5 speed gearbox, on a good condition car written off for only a small bumper ding, recently bought back from the insurance company, what are the odds!?!
I guess even if I don't end up doing the engine swap, it's still easy to put back on the road for someone, and if not then parts galore. Unfortunately space for 2 estates is a luxury I can't afford, but hopefully a solution will present itself before long.
Thank you to everyone who responded, I think the crisis has been averted (for now!) and hopefully I'll be able to help with parts for people in future.
Moral of the story: find an insurance company that cares about your car as much as you do.