Ignition switch "Run" position
Does anything in the cluster..........which is switched by the keyswitch........work? Such as warning lamp(s)? That would give you a clue what might or might not be getting power. This might help when/ if you get the cluster out
Printed circuit pins repair
And if you are unaware, you can download the 73 shop manual, free, from MyMopar. That manual and several others over there came from a few of the guys right here