If you are really serious about trying to build a fibreglass boat from your mold, I have a copy of Charlie Walbridge's book that I could send you. It's not the last edition, but still has the relevant information. Do think about it seriously though, as it is indeed not a trivial project. You really want to be sure that the resulting boat will be a design you can be happy paddling. I should also point out that many, perhaps most, of the 'glass boats are first built as woodstrip models (plugs), and then molds are pulled from them for mass production.

You might try checking with the British Canoe Union for a local canoeing club and see if some of the older members have experience with 'glass boatbuilding. Here in California it's been 20 years or so since people routinely built their own boats, but for the river pioneers before the advent of plastic rock bangers the motto was "Build them light - and often."