Someone’s already come up with a way to merge the soundtracks here:
There are two variations: one, in which the most complete tracks are selected from both to form a more complete 1:29:41 version, and the second, in which editing is required to form an even longer version at around 1:42. I followed the suggestions there for the most part, except I reinstated the Star Wars theme and put the “concert versions” at the end.
Unfortunately, I must agree that this is John Williams’s worst Star Wars score; however, I must disagree with Alderaan in terming the third best Star Wars movie to be “bland and derivative” itself. 😃