I'm considering purchasing an '81 380SL that's in very good condition, both mechanically and cosmetically with the exception of the transmission. It's shot.

My questions are:
1) Is this something that I can rebuild myslef? I've rebuilt motors and transmissions in American cars, so I'm mechanically capable.
2) If so, where is the best place to get the parts? Is there a kit with the usually needed stuff available?
3) If this isn't something I should try to tackle, what sources are there for used/rebuilt transmissions?
4) What year and model Mercedes transmissions will work properly in this one?

Thanks in Advance,
Wendell Allen