Here’s the best view of the nut.

Never mind, pic didn’t upload.

Try loosening the idle screw on carb or different strengths of spring

That spring is very sensitive.  Moving/adjusting the "tip" of that bracket 1/8" can cause rpm's to change roughly 600-1000RPM's.
 
 
 
https://www.youtube.com/watch?v=XbFyGRixoGA
 
About 6 minutes into the video (he's goofy but knows his stuff)..
 
 
.

All right, trying to open the stupid engine up I hit it with a rubber mallet and broke the flange around the bottom where it attaches to the deck. So I’m off to buy a new mower, thanks for the help.

Update:
I’m the most stubborn SOB in the known universe and I have the high blood pressure to prove it. So I got the engine apart. The governor arm wasn’t anywhere near the governor itself in side the motor. I’m not sure how that can happen and I didn’t see anything that looked broken or missing. So I put the arm/governor back in position and put the engine together with some fresh oil. I cranked it and bent the little arm until it sounded right and it’s currently working. I’m going to mow and see what happens.

If it's now running good after testing, I'd drill another hole near the now broke one.
 
Drill thru the motor and deck (make sure it's flush, or shim it) and it'd work.
 
It ain't the space shuttle!!

It seems to be running ok. I don’t have a way to measure rpm, but it cuts fine.
Thanks a lot for the help. I think I’ll stay around this forum.