Saving Old Seagulls

what is the differences between Century plus and Silver one just the colour?
I can see on the motor I got offered that it is mainly black, but I don't know if thats original. Rusty colour has a part too. As far as I can read it's a motor, that's not suitable for my dinghy, and with all the problems people have with their Gulls, i better get one that is. But my English !!!!!

The major difference is that the Silver versions had the Amal carburettor, which delivered more fuel and generated more power.

British Seagull reckoned a 25% increase in power, and they advertised it as such, Mind you, they advertised lots of things in a way that today would be just plain illegal. The Hydrofan propellor, they said, gave 10% more power, the 'Insulastic' transom bracket was made of 'Polished Ivory' and the original Marston was 'guaranteed silent in operation'

Even so, it's a decent motor, and opening out the air intake on the carb to the same diameter as that found on the later plastic versions will make it go a bit better.