Thanks for the links, etc.
Thanks Celt and Desert Lobster, that's what I was after!
It's interesting that they chose March to do the traverse, that would definitely be a bit more challenging than a spring or summer attempt.
This route definitely deserves "classic eastern mountain ultra" status, if there is such a thing. To be able to attempt it near the solstice, all by daylight would be extra sweet, but I think by then the grass, blackberry bushes and other vegetation would slow you down and soak your feet more.
edit - It appears David Horton did it some time after 1991, starting at 12:03 am on March 21, total time 23:11:50, under snowy conditions. Quite a feat!
The thinking was to do the attempt on the first day of spring. I am quite sure it could be done in the 18 hr range or less under late spring conditions.