Yes johnfitz, you might be in luck..
I have had adequate success with Sound Forge 11's new "Sony Noise Reduction". Niiiiice improvement over the previous tool.
Highlight a 10 second sample and get a "Noiseprint" of the offending buzz, then go back and highlight the complete noisy channel, and apply the tool.
If you have two noisy channels, get a noiseprint of each one, and apply the tool to each one separately, of course.