1940s Dirt Track Footage: Now in Color!

You most likely seem this amazing 35mm footage of dirt track cars shot in Southern California the 1940s. It hit YouTube about 10 years ago and still serves as one of the clearer films of early postwar circle track racing. Eagle eyes will spot a very young Jim Rathmann, who would go on to be the 1960 Indy 500 winner. Someone recently took the time to increase the resolution and painstakingly colorize the film frame-by-frame in Photoshop, which I though was worth sharing.
If you know anything else about this film (like who Dalzell is?), please chime in with your comments below!