Ed, I suggest you get in touch with the Nautical Research Guild. It maintains a list of people who are willing to take on such projects - and know how to do them. A lot of good modelers, unfortunately, don't.
I don't do this sort of work nowadays, but I used to do quite a bit of it when I was working at the Mariners' Museum. (That was a LONG time ago.) I got interested enough in th restoration of old ship models that I can rarely resist commenting on the topic when it comes up.
I don't have the credentials of a professional conservator. (Those credentials include graduate academic work in physics and organic chemistry, among other subjects.) But when I was getting paid to work on old models (e.g., the notorious Crabtree Collection) I got reasonably well acqainted with the standards of the American Institute of Conservators as they relate to model conservation. I urge anybody who's taking on a model restoration job to follow those standards.
I get really uncomfortable when I read about some ship modeler "fixing up" an old model. All too often the "fixing up" takes the form of "improving" the model - i.e., adding details and other features that the original builder didn't put there. That's not conservation. The real conservator knows that his/her job is to conserve the artifact - not to make it better than it was originally. I've seen all sorts of awful things done to old models in the name of making them "better" and "more accurate." I'll offer two particularly hideous examples.
The first was a big "builder's model" of a 1930s-vintage Japanese freighter at the MM. Most model enthusiasts have probably seen such models. Among their prominent features are their deck and rigging fittings, which are made up of beautifully machined brass parts soldered together and plated with (usually) nickel. The practical reason for the plating was that good, thin paints were almost unknown in those days, but the visual effect of those shiny, jewel-like fittings is pretty impressive. This particular freighter, which was about ten feet long, was unusual in that its fittings were plated with gold - until one of my curator predecessors got hold of it sometime in, I think, the 1960s. He grandly announced that "you don't see ships sailing around with gold winches and railings," removed all the fittings, and spray painted them black. He claimed he was "fixing it." As far as my generation was concerned, he wrecked it.
The other example is a French 18th-century "Admiralty model" at another famous American maritime museum. This one, like so many other models of that period, was built in the "plank-on-frame" style, with exposed, unplanked frames below the wales. Some so-called conservator, having figured out that a real ship built like that couldn't float (brilliant!), meticulously planked up the bottom. And another priceless historical artifact bit the dust.
When I talk to students about this I tell them about Michelangelo's statue of Moses. The artist was working from a defective translation of the Bible, and sculpted Moses with horns sticking out of his forehead. Should the conservator get out a chisel and remove the horns? Obviously no. The builder of an old ship model presumably wasn't Michelangelo, but the difference is none of the conservator's business.
When I took on a model conservation job on my own time, I'd always tell the owner: "If you want a model built to modern standards, hire me or somebody else to build one for you. But if your model originally looked like a piece of 
, it'll look like a piece of when I get done with it." A modeler who views an old model as a vehicle for showing off his/her own modeling skills is no conservator.
Three other principles of conservation sometimes conflict with each other, forcing the conservator to make a tough decision.
One is the use of original materials. Please don't use styrene plasic when restoring a 19th-century model.
The second potentially conflicting principle is the use of durable materials. You don't want the work you do to fall apart in a few years. (Case in point: lead, including lead-based solder. Lead is one of the most unstable of materials. And please, please don't dye sails with tea or coffee. They contain tannic acid, which literally eats fabric.)
The third principle is reversibility. Ideally, a good conservator makes sure everything he/she does can be undone. (if any later conservator ever concludes that the experts who restored the Cistine Chapel ceiling made a mistake, that new conservator will be able to remove the work done in the 1980s and start over.)
Sometimes it just isn't possible to solve a problem in a manner that's simultaneously authentic, durable, and reversible.In such cases the conservator has to decide which consideration should take prioity.
There's one absolute rule: keep good records. The conservation project from which I got the most satisfaction at the MM was an 1876 model of an American lightship. Two of us worked on it for several months. Every day or so we had the museum photographer take pictures of what we were doing (and uncovering), and when the project was done I wrote a 30-page description covering every step. When I did private jobs I gave the owners photos and written records.
I can't make people follow these standards. But I hope any Forum member taking on such a project will take them into consideration. And if you get into a problem you can't solve, please get in touch with a trained, professional conservator.
Sorry to bloviate so long, but I think this is an important subject.