Thanks for all the replies and opinions. It seems there' a lot of different ideas on whether to keep it or replace it.
I've decided to go ahead and re-use this clutch for the following reasons.
1) Yesterday, I cut up some rags, laid them on the friction surface, and soaked them with Evaporust. Every few hours, I pulled the rags and went over it with Scotchbrite. By the end of the day, the rust was gone. There is some tiny pitting where some of the rust spots were but no scoring or grooves.
2) Although it was bought in 1984, it doesn't have a lot of miles on it. The car was a fair weather driver for four years, stored for five years, and then saw very, very limited miles until the car was disassembled in 2008.
3) As far as the clutch pedal effort, I've always been fine with it. I like a firm clutch feel.
4) It isn't rusty any other place that the friction surface
5) A situation I'm sure lots are familiar with, I'm on the home stretch of this restoration and so far, have spent over double what I ever thought I would on it....with more to go. Every time another unexpected $100, $200, or $300 goes out the window, it starting to sting! Anytime an old part will still function properly and I can make it look good (looks not an issue with the clutch), I'm trying to reuse it.
When I take the flywheel to have it resurfaced, I'll see if they can do the same on the pressure plate. I'll definitely be getting a new disc though.
Thanks......Dave