I bought the fibreglass moulding for this hull in 1981 and clearly it has taken a long time to get round to building it... I bought it from Aero Nautical Models in Camden Town and have long thought it was a Kingston Mouldings Hull. Since their hull is 40" long and the Aero Nautical Models one which I have is only 36", I was wrong. The plan is MW/1328 from the Model Boats plan service - or at least it was then!
It got a bit flattened in my suitcase on its way to Australia, and 34 years later it took some fiddling to get the internal ply frames the right shape and in the right place to straighten it out. I bought the 'Heat Resistant' version - at £16.80 it was £3 more than the standard one - but I have already managed to scorch the inside where a burner flame touched it, so how heat resistant it is, I have yet to find out. I doubt it is very resistant at all!
The photographs show that a lot of aluminium sheet has been added below and around the boiler area to shield the hull from heat,and aluminium is also used to support the engine and other essentials.
The deck is 2mm x 10mm lime strips glued to a ply floor, with thick black card glued between the strips to denote the caulking - very effective. Two removable sections are fitted, one over the rudder servo and the other over the boiler area.

The power for this boat comes from a three cylinder steam engine and boiler made by the Japanese company Aster, better known for their Gauge 1 locomotives. The engine is double acting but it's 'simple' not compound, and is identical to the engine they fitted to the three cylinder 'Shay' type geared logging locomotive. The boiler, which I will eventually lag and clad with timber, was originally fired by an Aster metholated spirit burner which relied on the heat from its own flame to heat and pressurise the meths tank and push meths vapour out of a tiny jet, and make a 'blowlamp' type flame which entered the flue. I found this extemely touchy and difficult to use and despite years of experimenting (I bought this in the early '80's too!) I gave up and bought a ceramic burner from Maccsteam which works well.

Finally completed after 35 years, must be a record! Boiler clad in balsa insulation and then mahogany strips. Four channel radio, throttle, steering, reverser and gas isolation valve - in case the prop gets stuck on something out on the water.
Hotchkiss 3 pounder made by 3D printing and forward cabin made in fiberglass on a 3D printed mould. All superstructure held down by magnets. Manual gas shut off valve under the gun.

Funnel is rolled brass and hatches scratch built from brass sheet. Very nice looking boat and it's a shame that the 'innards' aren't visible when its working.