Not getting 12 volts to coil

I want to thank you for giving me all the pieces (& then some). I have a 1970 Factory manual, but I have not seen the steering column connector diagrams in mine. I got 12.5 volts coming into the car from the bulkhead connector with the battery hooked up and only 10.5 at the batt 1 and ignition 2 end of the column connector. I'll try to clean (replace) the connectors that relate to ignition 1 and 2 that would directly affect coil voltage. I'm trying to avoid having to replace the ingition switch, because of 2 Miller-type tools I don't have. You have helped me, because I don't have an automotive background and I see the voltage drop depends on how much current is flowing. All my drop tests were done with the starter going. I've had my car 20 + years and have not used it much. It's stock (warranty block by casting date on the block) in relation to build date and 'clean' serial number plate from what I can see. Years ago, I used to get advice from Karl Pippart III, but I lost contact when his magazine folded.