Ken - stunning model, and a really nice finish, we are slowly continuing with th build of the topaz, we too are building the deck/ planking with black cartridge paper.....slow but steady !!!
as for steam plant then at present i am still unsure, i have had an offer from a chap form the hayes and harlington loco society to build me a steam engine for the boat, he has plans/ castings for an engine very very similar to the plant recommended..... not sure about the boiler though... so may go down that route and have the engine made and that way i can spread the cost as the engine comes along with stage payments !!!!.... currently i am building it so that an electric drive and 'fake' smoke unit can be fitted into the boat and bolted down into the hull, - that way i can run the model....then equally a steam motive power 'plate' can be substitued if so desired in time- a member in our club did this with his boat and so long as the access allows for this swap over and that weights and positions of equipment allow the COG to be maintained then its a duel fuel model !!!