I'd stick with the one you've got. Anytime you buy another car, no matter how good it looks, you inherit a whole new set of problems.

I think it'll be cool too if I can keep my car on the road for another 12 years so it'll be an antique, if you want to restore your 240, I say go for it. I wish I had the money to treat mine as it deserves.

Ball joints - easy. You can do it yourself with a Bentley and a modest set of tools.

Body work - are you talking about the spare tire well? Those are available as a replacement panel for like $40 I think. I've been hearing good stuff about Paintless Dent Repair specialists lately, they might be able to straighten out your fender without need for a repaint. Otherwise, buy another fender, and treat the car to a new paint job - you did say complete restoration, right?

Fuel problem - those can be tricky to diagnose, but once it's figured out it's usually easy and fairly cheap to fix.

Finally KEEP the manual windows. The less power accesories you've got, the easier it will be to keep the car forever. Also, manual windows are the rarity among later 240's in my experience, not power.
--
Sean - now frolicking in the Land of a Thousand 240's (aka, Fredericksburg) thrice a week.