£2.5 does seem a little steep, I have a 20 foot 1930 British Power Boat Company racing launch I paid 1800 squid for, its in a similar state but much much rarer (or course rare does not mean valuable...)
It would fetch over 20k finished, it makes a big difference if someone is buying to to do up themselves or entrust to a boatbuilder.
Its the sort of thing Peter Freebody buys and then waits for some rose tinted spectacle wearing fat walleted individual to wander into his web.....thats assuming he does not leave it to rot to nothing in his yard....