I would remove it. I've been amazed over the years at how much glass beads persist in remaining adhered to corners and crevices, especially in an oily location such as that. Even after several forceful washes with Dawn and very hot water. Followed by power washing.
I removed it, tapped the holes, cleaned with acetone and applied Loctite primer for inactive metals followed by red loctite. I used low-profile-head bolts.