Hi,
in 1996 I made a live steam model of "Mount Washington" using the kit by Dumas.
It was necessery to extend the depht of hull by 25 mm, for this I cut the hull above the waterline in two and set in a 25 mm wide ABS piece with the lenght of the complete hull. Later it was sanded, plasted and colored, a difference to the original hull wasn't visible.
For the walking beam engine I used cylinder, slide, excenter, flywheel and other parts from the Regner 12/36 engine, the frame I made of wood like the original. Because it was 1 cylinder, the engine neeeded a flywheel by 90 mm diameter and a 1 : 2,5 gear reduction by belt drive to the paddle shaft. To make the beam, I was able to use the original beam made of white metal by Dumas.
The 12/36 engine also today is available by Regner to a rather low price, it has a piston slide and so it's simple to reverse it by a reversing valve (also available by Regner).
It's difficult to start a 1 cylinder engine by radio control. This does a small electric motor with great gear reduction switched on and pushed against the flywheel by R/C when necessery. If the steam pressure is at least about 2 bar, the engine will run immediatly, when it's pushed above death point.
After some minor faults in the beginning the whole steam plant shows a nearly perfect function.
Normally the "Mount Washington" has a dangerous toplast. For further stability of the model there are removable rafts of balsa between sponsons and water. The rafts are formed and colored correspondending to the hull in white and red. One can be remove it in seconds, if the model is outside of water. When it's in, the rafts are unobtrusive within a distance of a few meters.
Unfortunately the model is 400 km far from me in the house of my mother, but I will see, if i have some photos here.
Tom