Thanks everyone for some great info. The talk of Seagulls brought back memories of car smells from 30 years ago. And ... I couldn't possibly buy a Honda after DW said it sounds like a horrid wet fart, so thats off the list. Emotional decisions!
Good pointers on 2-strokes still being available in uk, that led me to track down some 3.5 Tohatsu's. Am going to Soton today to look, and will see the Suzuki 4-stroke too. Jimminy said about twist grip throttle, now that could be important, I like to sit on the centre seat of the inflatable and use an old shroud cover as a throttle/tiller extension. It may come down to relative sizes of the 2 contenders.
Will report back. And thanks again everyone for much useful stuff.
Apologies to those who have heard this before. I have had a Tohatsu 2 from new ie about 14 years. It has had very heavy use, minimal maintenance, and been totally immersed in seawater three times. Last year I reluctantly changed the plug restoring its performance to "as new".
Just be sure to clean out the float chamber every year, run it in fresh water at layup, and keep oil in the gearbox; thats it.