Hi there,
Have a look at this link (a list of resources for building models of Brunel's ships):
http://home.att.net/~ShipModelFAQ/ResearchNotes/smf-RN-BrunelShips.htmlMany years ago, Model Boats magazine ran a long series following a chap (a reverend, I think) who built a large scale steam powered model of the Great Britain, he wrote a book about it - William Mowll, that was it. Details are:
S.S. GREAT BRITAIN The Model Ship
ISBN: 0870218662
Author: Mowll, William
Have a look at this link to somewhere you can order it from:
http://s-books.used-books.eu.com/Mowll,+William--S.S.+GREAT+BRITAIN+The+Model+Ship--0870218662--1.htmlIf in doubt, look at
http://www.bookfinder.com.
I have a book about the Great Eastern - no plans, but hundreds of photos, so I could scan stuff in for you if you need it for reference.
There was a really good site about the Great Eastern, a couple of chaps who were building scale models had accumulated tons of material, but I can't find it now (and I lost all my old links after a nasty computer crash).
Good luck, let us know how you get on!