With the intermediate gear/shaft between the speedo cable and the odometer removed it was easy to spin the digits up or down. Just using my finger rolling the first gear and I advanced 5 thousand miles in 10-15 minutes time---boring! I wish I could say it was this---or that---maybe just messing with it does it good.
A speedo story----Back in 1972 when we moved from the Catskill area to Buffalo I used a $50 1949 Chevy 1&1/2 ton Step Side--5 window, chrome bumper & grille farm truck. I'd been driving the truck for about a year to and from work with no speedometer or odo. Half way to Buffalo, on the back country roads appropriate for the truck's 45mph speed, the speedo and odo decided to start working. Guess it liked the open road. -- Dave