Mid 20's AC Speedometer wheel yokes are made from pot metal.  They were used in 1925 to 1927 Buick and Chevrolet speedometers and likely several other makes.  Feel free to tell me other dates or vehicles used.  This part disintegrate over time and the speedometer wheel stops functioning.  Sometimes the disintegration is minor, other times it is catastrophic and this part cannot be repaired and must be replaced.  JBweld will hold some of the better ones together for some period of time. I ha