Problem Resolved
I just wanted to add this in case anyone experiences a similar problem: start with the simplest fix and work your way up. No brainer, right? After replacing the speedo cable and speedo gear, which has 44 teeth on a stock m1008, I found a web sight that repairs speedometers. There FAQ page said that a bouncing needle is sometimes caused by the oil in the speedometer drying out and dust collecting in the speedometer. I lubed the speedometer with CLP and all bouncing, except at around 10-15 mph, has stopped. Hope this helps the next poor sucker.