Sorry to necropost, but the reference here has been amazingly useful, so wanted this to also sit alongside as a thanks to those who have gone before. I've been obsessing about small hand props lately and stumbled on this older thread - started work on my own Death Star conference table cup. With an original Tupperware found object in hand, I've modeled an accurate (outer dimensions at least) printable Jel-ette mold base for the cup:
The fact we haven't identified the upper cup is frustrating, so I've had to eyeball a bit of the design and execution of that part. I'm going to make my replica a little less "screen accurate" by painting the chrome versus using aluminum tape, so I included the troughs to allow for some dimensionality.
Just for anyone doing a real found parts hunt for the actual cup from ANH, the dimensions we're likely aiming for are roughly 73-74mm in diameter and 70mm high, give or take. I would wager it was from the Tupperware catalog - a short tumbler of some sort.
I'll update when I get this complete - once I know I'm 100% happy with the files I'll drop them over on Printables.