Sorry, tommy, but he means Holman Williams, not Holmes and Williams. http://www.ibhof.com/pages/about/inductees/modern/williamsholman.html
I've seen brief footage of him (about 30 seconds worth). I think it may have been on a Joe Louis undercard. So it's definitely out there.
It's unlikely we'll ever find more footage of Holman. Untill 1940 a federal law prohibited the transfer of fight films across state lines making it unlikely that any footage will ever turn up abroad where film has been better preserved. A whole chunk of nitrate films from the 1940s were lost forever in the 1978 national archive fire, part of that collection that burned included sports footage from around the time Holman fought. Unfortunately, we'll probably never get to see film of what many people of that era consider the most skilled fighter that ever lived.
It looks like it was shot on a home video camera. Surely, there has to be more of that film beyond those snippets.