My preferred method of matching footage is to render out a representative sample of the "master" footage (the corrected Varicam footage in your case), then importing that footage into the Color Finesse Gallery.
You can then select that footage as your Reference "image" and can scrub around in it to find something to match to in your 5D footage.
You can use still images, but I find rendering to a QuickTime movie gives me more choices when looking for a match. You can split screen with the Reference to easily see differences in skin tone or whatever you're trying to match.
Bob Currier
Synthetic Aperture