I don't recall whether anyone has already provided this information.  If so,
I apologize for the redundancy:
--------------------------------------------------------
A video version of Hal Holbrook's Mark Twain Tonight! has arrived at last.
I have a copy, but haven't had a chance to view it yet.  It's available
from:

Kultur International Films Ltd.
195 Highway 36
West Long Branch, NJ 07764

PH: (800) 458-5887 (for ordering)
Web Site: www.kulturvideo.com

The box indicates that it's the March 6, 1967 TV version and that the
running time is 90 minutes.  Price: $24.95 + $3.95 shipping.

Jim Leonard