This boat; made by A. Thierens & Sons, Trafford Park, Manchester; was made in both steam and electric versions. The electric version was called the Electra Cabin Cruiser. This steam version is known as Firefly. It is powered by a modified Mamod Minor 1 engine.
The hull is a contemporary cabin cruiser style with a low profile cabin, part covering the boiler with the funnel passing through the roof. It has a flush deck and a flat bottom, with a simple rudder and an angled stern tube for the propeller.
The boiler and firebox are taken unmodified from the MM1. They are mounted on a plain flat base which also supports the simple engine bracket. The burner that came with the boat as acquired was a standard Mamod three wick type. I don't think this is what was originally supplied because it is a tight fit to manoeuvre into place but is unconstrained when it's in there. The boiler is 1 1/2" diameter x 3 11/16" long. It is fitted with a standard Mamod safety valve and the funnel, which receives the exhaust steam.
The cylinder appears to be the standard early MM1 type with a disk crank/flywheel. The propeller shaft is fixed rigidly to the flywheel and passes through the stern tube to a two bladed propeller - 1 1/4" diameter. The rudder is mounted directly behind the propeller and is connected to a plain tiller on top.
Mechanically, the boat appears to be in fair general condition. The paintwork, however, has been re-done to a mediocre standard. The paint is thin and is flaking on the bottom of the hull. Elsewhere, it has been unevenly applied. The colours, I think, are at least approximately correct. I have repainted the bottom to protect it from the water.