Reading this article makes me wonder if our astute researchers have searched this possible resource of lost fight films... http://www.cnn.com/2010/SHOWBIZ/Movies/10/21/us.russia.found.films/
You'd be surprised what you can find. That's why I always try to search boxing uploaders on Youtube who come from Eastern Europe. Even though I don't understand the language. I'm always finding U.S. boxers in their videos. Here's one I saw the other day that includes Tyrell Biggs. https://www.youtube.com/watch?v=aGUA5rw528Y I found another with David Bey sporting a huge afro. I know you're referring to turn of the century bouts, but still. There's a lot to discover.
it's possible. alexander karelin, the 3 time Olympic Greco roman gold medallist had NOTHING posted online of his. then one day, voila' he had a dozen or so matches.