I want to buy an 81 to 85 300D turbo diesel in the next few weeks.

What I would like to know is two-folds:
- Any tell-tale noises/leaks/things-to-check that can forewarn of impending mechanical doom or costly repairs?
- Any part(s) to check for rust in particular? I live in Montreal, Canada, and we get a lot of snow and salt on the roads, so this is a major concern of mine. If there is anywhere that water can accumulate or that rusts first, I'd like to know.

Thank you very much for your help.