Short history: bought a 1995 Volvo 440 1.7L Turbo, had trashed auto tranny. Replaced tranny, as well as multiple MOT violations, so I have invested a lot in this hunk of junk. Now the driveshaft does not seal all the way with the tranny, causing a major leak of fluid everywhere.

My questions to anyone interested in replying is:
Is it worth replacing the driveshaft?
How difficult is it?
Where can I get a proper part for cheap to replace it?
How do I determine what driveshaft is the right one?

The tranny replaced on mine came from a 440 that was the same type, but the model was a few years older, so it took some modifications to put it on. Hence the driveshaft that is on my car is a tad shorter than the one the tranny came from, and there is a gap, even though the car drives and shifts fine.

Thanks for your help in advance, this thing has been nothing but a nightmare since I bought it, and I would like to get a little use out of it and then sell it eventually. Cheers.