looks like the front cover was spinning from the wear pattern

Quoting Removed, click Modern View to see

new gov. on the way also found the threads on the cam shaft are striped / have a used cam coming also $25. bucks plus $8. shipping 30 return / can't beat that. Thanks for the feed back

Changing the cam with the engine in the tractor is a very difficult job.

Did the cam come with the lifters, kept in order? If not a set of reground lifters would be a safer option. Even that is risky...

I believe the tab stops against the lever arm of the actuator assembly. One locates it at 8 o'clock during assembly so it only moves a few degrees before encountering the arm and doesn't sling around and impact it hard.
In this case, the photos indicate the governor bound up with the balls out at the extreme and operated that way for quite a while before catastrophically destructing. It would take some time to wear all the divots to the extent they are. The mechanism could not have been working.
Dunno - I'd get a new governor and install per the I&T manual instructions and carefully adjust the system, making sure all parts are present and in good working order.
These governors are not the strongest design, either for function or longevity.

Wish I could picture in my mind what the tab is supposed to stop against. It should be obvious with the cover in hand. I would take some straight edge measurements with the new governor in place to be sure the depth of the tab is correct. The use or not use of the spacer is important. Best I remember, the ball cage should fit flush to the front of the cam gear, not stressed or bent as the nut is tightened. It should have instructions what to look for.

The governor cover tab is supposed to be positioned at 8:00 when the timing cover is installed, so it will not be crushed and will turn around to the proper stop when started.

Here's a how to if you don't have the shop manual.

Pay particular attention to the nut torque in the video!

• Governor Replacment