I hope my recs are in time for your trip still. I asked these questions to a friend that lives in Port Townsend, and here is his reply.

Nowhere that is great for fish & chips. Sirens Pub and the Old Whiskey Mill have fish & chips. The best restaurant in town is Finistere. You will need reservations and they have a nice outdoor patio that is fairly well protected from the weather.

Fountain Cafe and Alchemy are other decent choices for restaurants.