GB, I have "restored" a number of pieces over the years without sanding and ruining the patina. It doesn't always work, but I pour lacquer thinner in a small metal tray and dip #0000 steel wool into it and rub it over & over the finish. Lacquer thinner will dissolve most film finishes without totally removing them. You can still spot sand any really rough spots and then blend them in by using the lacquer thinner and steel wool method and feathering in the old finish. When you get the results you are looking for, consider a couple of coats of polyurethane as a top coat and to prevent future damage from water and/or alcohol. Try it on the underside of the table top to see if it gives you what you want without making it look "new".