Well as a business man everything has a market - its just is that maket > then your cost/time....Figuring out that profit margin is the real trick now isn't it. 
There is no trick - you can never
really make a profit ,if you take into account
" Time & Materials " in the boat buisness!
To me it is
" Therapy " ! I usually keep 50 % of my Restorations for about a year , then put them up for sale . The last two daysailors that I restored were a PEEP Hen 14 and a BAY Hen 21 by Nimble , I had a waiting list of " Hensnest " customers for both boats and sold them after I played with them for about a year .
Also Restored Three -Boston Whalers 13 footer's , Aquasport 20 and a Mako 19 CC ( all power boats ) ! And had a market for all of them ( very easy to sell ) .
So, Adam - is there a following on these Herreshoff 18 footers i.e. Harbor Pilot ?