185 VS Ranger 150 Merc: Had the boat covered all winter but left the drain plug in

and the bilge flooded covering the 3 batteries, 3 bank charger; corroding the terminals & cables; hot plate also affected!]
Question: Is this repairable and does anyone have a recommendation for service??? I am in the Tri-Valley "Area and am just looking for someone reputable who might be able to handle this