If the rib is solid from the rear sight forward, and the under-ribs are sound, it may not need re-regulation.
Nice little ULH double BTW.
If it was just me (and the price was right) I'd take a chance on it and tin the rib back down to see what happens.
Not like there's a lot of recoil to stress the repair.

Certainly understand erring on the side of caution tho and sending it back!