Try Bob Day at R&D Custom Barrel in Pico Rivera, 310-283-0046
Or Bill Skinner in Temple City, 626-222-8818
Or Lucio Sosta in Azuza, 626-969-8989
Bob, Bill, and Lucio are the smiths that Pacific Sporting Arms uses for their customers. I have had work done by all three with good results.
You could also try Lazlo Lukacs in North County San Diego, 760-231-9358. Or Bolsa Gunsmithing in Huntington Beach.
FWIW, I have a Red Label Sporting O/U with a sticking safety problem. Had it worked on locally, and the verdict was that fixing it required a proprietary tool or fixture that only Ruger has. Called Ruger, they confirmed that. Reassembly issues on your Gold Label may not be your fault.