Hadn't heard this before either.
I remember going to Hannibal on Memorial Day in 1985 and joing in a town party lining
Hill St. Up the hill, a series of rock bands played ZZ Top and the like
while the community sat around in lounge chairs and such and had a great evening
out. I recall thinking, had young Sam Clemens
grown up in the rock era, he'd have been up on that Hannibal stage just like
John Lennon or Keith Richards or the like, playing music
and having a great time.
Just a flash of humor, but never made much of it
until your note. Maybe I was onto something . . .
can you see Twain as a young Elvis?