A good place to start might be the Steamboat Museum at Windermere, I think they have some literature with specifications of their exibits, with basic plans. The great industrialists that lived around the lake used to use the launches to comute from Lakeside house to the Railwaystaion during the 1800s. Shepherds of Windermere built lots of the big Lake launches 1950s? that one sees on the Lakes, they might have some old plans tucked away.
Sounds like a huge undertaking, where do you intend to use it?
Thanks for that. The museum is closed until March. A friend of mine who
works at Shepheards is on the case for used plans.
It will hopefully be commisioned for one of the Lakes