Hi All
I took the engine apart and cleaned it all throughly. Got hold of some good second hand rings and replaced the existing ones, cleaned the carby and generally serviced the engine (new spark plug, air filter etc..)
Put engine back on base and it now runs mint. Starts first pull and sounds great. Idle speed is a little high but that is of no concern to me.
All up cost me about $20 to fix.
I still can't understand the money the mower shop said it would cost.
