I appreciate any helpful input I may get from you all. I finally have my new to me 1971 240z running and idling on its own.
I decided to try and tackle figuring out why my gauges were not getting power. I went to the fuse box and found a fuse missing that I think supply’s power to the dash. I placed a fuse in this empty slot and, behold the three dash gauges are all functioning as they should. Happy and relieved I went to turn off the by turning the key in the ignition. Key all the way out of the steering column and in hand, car still is running…… puzzlers I go to the engine bay and remove BOTH battery cables from the battery and the car continues to run. Baffles and confused I pulled the ignition lead to kill the motor. 
what could be the cause of this? Only thing I did is install a missing fuse. With the fuse out of the box, the car will shut down when I pull the key. 

Has the alternator ever been changed out for an internally regulated alternator? The lamp (switched) wire can backfeed into the ignition. The solution is to use a diode in the alternator circuit on the appropriate wire to prevent the backfeeding from the alternator to the ignition circuit. http://www.zhome.com/ZCMnL/tech/280Alt.html

I did install an internally regulated alternator from a 280zx. When I did this though I installed the plug that msa sells for this upgrade. I thought this was to make it a ply and play affair and had the diode inside….

12 minutes ago, Dcreech0 said:

I did install an internally regulated alternator from a 280zx. When I did this though I installed the plug that msa sells for this upgrade. I thought this was to make it a ply and play affair and had the diode inside….

It should have, but diodes can fail, or someone could have installed the diode backwards.  If you have an ohmmeter, I can tell you how to test the plug later. Right now it's time to work on my car.

Don't take it apart if you find out it's bad and don't want to fix it yourself.  I wonder if  @Zs-ondabrain is still out there somewhere.