This is a no brainer - send it to Briley in Houston, or Mike Orlen, or any other competent gunsmith.
Even not knowing the gunmaker, I suspect it's fair to say that done right, you'll likely keep it forever; done poorly, it's just another gun that needs fixin' by its next owner - if there's enough steel left.
FWIW, I shoot a very lightweight 28 SxS often, exclusively with 5/8 and 3/4 oz 7 1/2 loads [RST's]. Briley reamed both barrels to .011 [LM] and this works very well for me for both dove and quail.
JMHO.
