I am looking for information and/or a source for fuel guages from an early 1960's chevrolet. The guages are round and manufactured by ac spark plug division of General Motors. The two numbers stamped on the sides of the quages are:

P/N:6432690
P/N:6430694

The guages are factory sealed electro/mechanical guages with the top crimped on over the glass. There is an access hole on the back and three threaded rods to attach connectors with.

These may have been used on boats as fuel guages as well. Any help or leads in where to source these parts or information is greatly appreciated
Thanks
Peter