Thanks to Ben Singleton at University of South Carolina's Moving Image Research Collections, here's a portion of the historic footage discussed above. The first scene is Ruth's sixth-inning at bat that, by comparing to the play-by-play data, helped confirm the date of June 1, 1925. The second scene shows Ruth outside the Yankees dugout prior to the game. The final scene shows Ruth in the dugout, with Lou Gehrig in the background at far left. (Also on the bench, but at the right side of the frame, is Yankees center fielder Earle Combs). Enjoy.
scroll down to the March 25th update for video
http://baseballresearcher.blogspot.com/2014/03/some-very-fortunate-footage.html