Today I was down at the used bookstore when I happened upon a boxed set of Knight Hawks, the spaceship expansion for Star Frontiers. It was six bucks. I grabbed it...and thought it seemed a little heavy. It was rubber-banded shut, so I just bought it blind.
The bad news: It's missing the spaceship chits and some of the stuff for the "boardgame" part of Knight Hawks.
The good news: It contained extra copies of all the books in Alpha Dawn, plus six modules for Star Frontiers! It also contained the stats for an AD&D beholder, written on a 3x5 note card. It did have the rpg/campaign stuff for spaceships, even if the boardgamey stuff was missing.
I think the stuff for SF is all available online, so if I ever really have a burning desire to play Knight Hawks, I can just download the counters and put some cardstock in my printer.
...realistically, though, I'm more likely to just convert it all to SWN. ;)