Just thought I'd post an addendum to this thread: they're still updating this proggy. It seems most of the work is towards the MorphOS and Warp versions, but there was a 68k update on February 18, 2002. And they've added screenshots from The Dig and Full Throttle, so it seems those games are now working (not sure which SCUMM version, though). At any rate, it seems they have music working now!
There was also a little blurb about Amiga SCUMM at Amiga Rediscovery
that might be worth a look.