Hi Bill
Try Seaport Model Works, he offers a resin sardine dragger and a couple of other boats in "N" scale.
I used to be into "N" gauge, I built a small "test layout" that was built on a half sheet of plywood just to test my modeling/train skills. One "business" that I had on the layout(it was based on the Maine Central's Rockland coast branch, was a oil storage/distributor company. Since it was on the water I utilized Lindbergs tug boat and dredge(converted to an oil barge). I'm not sure if Lindberg is going to release the 4 boat set(fire boat, tug boat, river boat and dredge) again, they are "N" scale in size and appearence, with a little work they can be adapted to any time period. I also had a waterfront lobster business with a couple of Maine lobster boats built from plastic "lifeboats" found in the 'ol parts box. And of course a Coast Guard station with Buoy tender(made from the fire boat). I also had a model of a Texaco oil tanker(the old gas station premium from the 1960's) which is very close to "N" scale that I envisioned as part of my "giant" layout that I never built. If you like to build, there are a number of boat hulls that can be adapted for "N", I believe Lindbergs Harriet Lane could be modified into a large ocean steamer(paddle wheels and all) from the 19th century.
Keep in mind it's the port holes, hatches, walk ways and ladders that can transform any hull into "N" scale, along with some scratch building.
Well good luck on your project, one thing I learned from "N" was that good eye sight and nimble fingers are essential. And also KATO RULES!
Warm regards
Mike M.