Have had it running, this was fitted to a post war 12 foot aluminium launch, It's a water cooled horizontal twin, previous owner had the twin ignition coil rewound by Villiers services! But never ran very well. It turns with compression, bearings appear OK I suspect it may have been a problem with cab flooding? It's complete except I used the transmission reduction gear  when I fitted a different engine in the aluminium boat,  now having a clear out. Apparently these engine go back prior to the war and wear used by the military in canoes? Then post war fitted in small boats. It weighs around 18 kg so collection only from North walsham or arrange your own courier services.