Fatigue cracks

After Removing the front panel from my air compressor, I have treated the surface rust. I need help on how to tackle the fatigue cracks around the lower mounting holes.

If it was me, I’d bevel the cracks then weld them and grind flush. Then I’d add a stiffener plate, larger then the stress area, under each hole and weld them in place.

I would say, pull it all back together, weld it (total weld), clean up the weld, weld a 3x3x3/8 angle as long as you can fit on the inside, redrill the holes, this should hold longer then the truck. BEFORE installing the angle, PRIME EVERYTHING using a epoxy primer if possible, this will keep rust from building up between the angle and mount, also keeping the weld area from rusting.