57 speedometer help

[brownsville]

Hey everyone I was wondering if anyone could help me out with my gauges on my 57. I am using the factory cluster and have logged almost 4000 miles since it was made drivable. The problem I have is that the speedometer just all of the sudden stopped working (after bouncing here and there) it has a new speedo cable and doesn't appear to be in a bind. I was curious if maybe the gauges have gotten to much dust in em and need to be cleaned out or if it just needs a new cluster. I am trying to not spend a $150 on the gauge and if I could fix them myself that would be great. If anyone has a link on how to repair them that would be great (or helpful hints) Thanks in advance