Gauge cluster questions

I just bench tested my new voltage limiter with the cluster. The temp gauge started working again right away. No dice for the fuel gauge. Took the nuts off the back of the gauge cleaned them up and cleaned up the circuit board where they contact and presto the fuel gauge also came to life. I'm going to take the cluster all the way apart and clean everything real good but I just wanted to make sure the gauges were at least functioning. 42 years of crud and this was actually a very clean garaged car from an old lady. Clean clean clean...