..thanks, all, for the kind comments and encouragements ..it just occurred to me that, even though I've messed around w/ slide for years, this is the first 'song' I've really worked up that has any form to it.
git-fiddle, I'm tuned to open D-type tuning but tuned pretty far south of D..this should be a decent tune for lap style, even w/ only 6 strings. You should be able to dampen easier and get a cleaner sound..once you have the basic riff structure that McTell uses throughout the verses, and the intro, it's pretty clear sailing, and, like others have said, it's just playing it more and more to iron out the rough spots.
OK, so can we set our sights on Aug 19 as the BWM tribute date? ..let's get those 12 strings revved up!