The 70 key buzzer is on all the time ???
Any help

I'm not familiar with that, but would make a person think something is touching something that it shouldn't be, or something is stuck??

What's the purpose of this buzzer?

All the time, or just when you remove the key and should normally shut up?

Try spraying some electronics contact cleaner into the switch.

As a side note: I would like clarification about a couple of the wires comes from the ignition switch.
In particular, the wires labeled P and S

Not sure about the 70, but later would be the seatbelt wiring circuit

When you turn the ignition off and remove the key, the cylinder should make a "click" noise and that's when the buzzer should turn off. So possible the ignition lock is sticking or defective.

Is the key/in the ignition buzzer a result of the key and tumbler completing a ground ? And, when the key is removed. The griund circuit is broken; or something like this. ?

It's really a mechanical thing in the tumbler. If the the tumbler doesn't come back out flush after you pull the key, the buzzer will continue. If your tumbler is flush when you pull the key, yes, you have some kind of electrical contact issue. Mine is 50 years old and sticky, so I have just learned to pull it back out when I remove the key by pulling it at a bit of an angle, giving it enough resistance to pull back to flush.

I would be heading to my locksmith, probably a simple thing for a qualified tech

There are no electrics, or grounds involved with the key switch, or the steering lock. It's all in the electrical switch on the rear of the housing. Unplug the sensor on the seat pad!

Thanks for everyones input about the buzzer.
Sorry for the long time in responding.