Thank you for taking the time to respond Ivanerrol, and ps2cho.
Does that mean you were a former Channel Islander, Ivanerrol? (tell me you weren't a crapaud

!!) - sounds like I have the same model car as you feature-wise (or lack of features).
I read elsewhere that your present home country and other parts of the world have low octane petrol such as those you mention. In the UK and CI you cannot get lower then 95 at the pump and 97 is available as 'Super Unleaded'. The EZL is set as appropriate for 95 RON.
I twiddled the idle adjustment and now it sounds like its almost going to stall when stopped in gear - not a simple thing to play with, clearly... will have to tweak that back to normal now.
The air temperature recently has been around 5.0-6.5C according to the dash readout and I have noticed the engine temperature has not gone much above 40C and from reading other posts on this site the engine should be at 87C under normal conditions. I suspect the usual cheap-o-mechanic job of not fitting one when the water pump was replaced, if not simply rusted 'open'. Some replies to those posts suggest that fuel economy will suffer as a result of the temperature sensor not detecting a warm enough engine to switch off the cold-start injectors, etc. As this should be cheap to replace I will venture down this route next. Might driving with 'choke' effectively on impact on performance?
Regarding the spark plug gaps, ps2cho, I asked the parts guy whether I'd need to adjust them and he was fairly sure they were correct being OEM items - but I intend on checking the condition of the new plugs and cleaning them as necessary so I shall find the long-lost feeler gauge and verify.
As a general question on coils do they really become 'weaker'? I would have thought they either work or fail. I am happy to replace the coil if someone can confirm that changing a coil gives a definite improvement?
Many thanks,
Glyn B.