I can't give any direct help with a mentor, but the best resource I know of for fibreglass kayak building, especially for whitewater, is Charlie Walbridge's book. It should be available through whitewater shops such as the one at Nantahala, and through Amazon.

As others have mentioned, building a glass boat from scratch is a multi step process. First you need to build a plug, and then use that to make a mold and then the boat. While very few people build boats from scratch, paddling clubs used to have molds for use by their members. Perhaps you can find one of these - although it would almost certainly be a much different boat than today's designs. The alternative dear to this BB, and the way many plugs are made, is to design the boat to the point of having the frame stations and then build it in wood strip construction. This is essentially a fibreglass composite boat using wood as a core material rather than the cell or foam cores used in very high end boats. It will be as robust as straight glass layup, even more so perhaps, but will hurt a lot more when you ding the beautiful wood core.

My grasp of geography in your area is weak at best so I don't know how practical it would be for you to visit them, but there are some builders of glass boats in the general mid Atlantic area. The biggest is probably Dagger, which makes composite boats in addition to their plastic lines. I think Phoenix is still in business, and a little research should turn up others. Look for companies specializing in race boats. There may be some 'backyard' builders out there that sell to local paddlers. These folk are probably quite willing to share knowledge and experience, and may even have a mold or two they would be willing to share.

Finally, if you haven't tried them yet I suggest contacting the Canoe Cruisers Association in Bethesda/Washington. If nothing more, they also have a bulletin board where you might get some help.

Good luck, and I think most here would be quite interested in hearing how you progress and in helping where we can.