I recently scored NOS service part regulators. The arms have a C7 #, the chassis body has C6 # stamping. Passenger side is galvanized, I assume it is much newer even though the boxes looked about the same vintage.
I dug them out to make sure they had the '67 shafts on both sides.
They were expensive. Worth it vs. the reproductions? For a part you might never see? Not sure I can answer that.
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