the speedometer works, odometer doesnt, but occasionally odometer will turn a couple of tenths of a mile? Any ideas?

Pull the entirre assembly out and check the pot metal gear that drives the odo.
This gear tends to start to slip on the shaft. If this is the case, tighten it up a little bit, and it should work again
Look for the Pelican (I think) article on odometer repair

Yep. Pelican has a tech article on this. Common failure. Not too difficult to fix. I did this several years ago on my car and it works great.

Repaired mine, works like a champ since.