Pioneer USA:
50-461A3-02 21A50258
50-461B3-18 19A51640
50-461C2-20 19A50732
Pioneer Japan:
50-461-A03-P 09A02111
50-461-B08-P 09A01979
50-461-C02-P 07A00900
UD-3-B70-P 06A00269
Mitsubishi:
C1425-85 A 02 A20G06444
C1425-85 B 03 B20G06784
C1425-85 C 05 C20G05400
Technidisc:
IMAGE ENTERTAINMENT "EMPIRE STRIKES BACK" SIDE A Technidisc #433-083-284G 05/25/94H
IMAGE ENTERTAINMENT "EMPIRE STRIKES BACK" SIDE B Technidisc #433-083-285J 07/26/94A#
IMAGE ENTERTAINMENT "EMPIRE STRIKES BACK" SIDE C Technidisc #433-083-286O 07/27/94K#
WRONG SIDE 06/16/94XX WRONG SIDE
The Technidisc pressings from 93/4 used a newly made master that has slightly better clarity & colors preserving the original theatrical presentation better than any other release; Similar to their Star Wars release that was taken from a new struck master also. Sadly the return of the Jedi image pressing was a reused master from pioneer USA.
I hate to contradict, but as far as I can tell, the Technidisc pressings do not actually use a new master, as has been suggested above. I have pressings by both Technidisc and Pioneer USA, and they look virtually identical (with even film dirt and jumps in the exact same places). In fact my Technidisc edition actually looks a bit noisier... which isn't uncommon for Technidisc. The colors on my Technidisc pressing are also slightly less saturated, but I don't think that has anything to do with the master. It's probably just because it was pressed at a different plant.