borisanddoris said:

How out of sync are they? Are they just the LaserDisc sides, or is it a matter of applying a delay when muxing, say to Harmy's DE?

There are gaps every mid-reel with lots of missing frames on all the pre-THX transfers of the trilogy (with the exception of SWE - Technidisc) so there's quite much work involved gettin them in sync with the GOUT transfers which are more or less complete frame wise. Darth_Mallwalker posted a great documentation to usenet some time ago on the ESB LD's he checked, great reference material for audio syncing.