you sure the gauges are bad!?
if they are both not working you should check the constant voltage regulator on the back of the cluster, very often thats the problem.
alllllso don't forget the same gauge cluster was used in the 57-60 f series & a modified version in the c series from 57 all the way into the 70s or 80s. also on some school bus chassis.
Mikie
near ottawa canada
64 econo p/u 58 merc m-100 panel