I am surprised @ the wear on the 4 spider gears, chipping I understand, but one heck of lot of wear on the contact surfaces, for the stated hours.
It appears they are through the case hardening in places.
So you are going to take it easy and avoid any "hole shots" then as time permits replace the worn items in the off season,----reasonable plan.
Wondering if nutting or safety wiring the bolt heads, is advisable.
The bull gear does put all the driving motion through those 4 bolts, I sure would like to see @ least 6 or even 8 bolts taking the strain.
