This week I got really lucky. Audio wizard Andrew Berlin (of the Blasting Room) came over to my dinky basement studio and helped me mix "I Just Want to Know Her Name" for 3 hours. He showed me all kinds of methods that I probably should have already known about and that can make a huge difference, like bussing to a parallel compressor to slam a group of tracks into a crunchy sonic pancake, and then only putting a small bit of it into the overall mix. Or using many stages of light compression and EQ, rather than a single compressor and single EQ that do lots of work.
So, I just updated the MP3 for this song, and now I'm happily going to work on the other tracks, trying to apply my newfound knowledge. If you listen to it and then listen to any stylistically similar ones (I'll Eat All the Pie; Come on Down), you'll hear the difference. It's fuller, punchier, and less muddy.
Amazing what a difference it can make to just spend a little bit of time with someone who really knows what they're doing.