The Crabber 26, despite its traditional appearance, is a new design and has only been on the market for a year or so. I'd be surprised if you can find the lines of the boat anywhere other than from the builders. I suggest you ask them if they can help -
www.cornishcrabbers.co.uk.
Does it have to be a Crabber 26? There are a number of similar designs/types that are popular subjects for models.
(Incidentally, if anyone is interested in the process of tooling and prototyping the Crabber 26, a series of Practical Boat Owner articles can be accessed through the Cornish Crabbers website.)
Good luck with your project Jose
Greg