Postscript:
Found a wonderful repairman who sprinkled magic bone dust in the low E-string slot of the nut, added a drop of "Zap" superglue, which made that slot a tad higher, and presto...no more buzz. This repairman is a creative genius in whose workshop I found a cello/sitar he'd made from two enameled cooking pots, a cello neck, a National-style aluminum cone, and some extra drone/buzz strings. Sounds great when he plays it...

Bark WOof