Others have spoken only truth!! But I would have to approach it from a market standpoint. In most locales, a 40-50 foot project would appeal to a VERY limited clientele. Factor in the situation of yard storage bills and the costs to relocate the boat to more acceptable work areas and, IMHO the value becomes the sum of the value of salvageable items (
winches, spars etc) and the negative disposal value of 20,000# going to a landfill!!
You didn''t ask this, but, realistically assess the manhour commitment (again, free labor) a project like this entails. It surely must represent something on the order of 2 to 3,000 hours (or a year to a year and one half of a paying day job!! I have 500 hours in my dinky little project!!
Not something to be approached lightly!!