>Does anyone know if Clara or her daughter ever saw Holbrook perform Mark 
>Twain?

I believe I've read that he tried out portions of his act for Clara (in 
relative private, presumably) before launching the original Broadway version 
of Mark Twain Tonight, and she gave it her stamp of approval.

-- Bob G.

P.S. I thought I might have seen that on the liner notes for one of the 
original albums from that show, but I checked and that's not the source, 
unless I missed it.