I ran across this nifty little bit of footage a while ago. It seems to have been intended for training purposes, so we get some very clear footage of boxers demonstrating standard boxing technique as of 1917 or so. It's a nice gauge of boxing's development (and how far it still had to go) since Corbett and Fitzsimmons. http://www.youtube.com/watch?v=ga4zLsMmkE0
That's the one with Mike Gibbons isn't it? Sadly what might have been Mike's biggest contribution to the development of the sport which was his footwork doesn't get much space in the footage. It seems like he was a good teacher though.