In between the rain showers, I have changed all plugs, leads, dizzy cap and rotor arm. ( I must say, plugs and darn easier than the Omega!)
I also changed the air filter.
I fired her up after all this and she was like a different beast... idle now appears much smoother and there is no missfire at all.
I also noticed that the little "squeal" I heard when it was in D has gone. At first I suspected a gearbox issue or maybe the pump, but actually it would do it for a second when the engine was being turned off too... so it was just something that happened when the engine was under load. Probably only an ancilliary.
After this, I thought I best drop the oil and change that. Sump plug is about 30mm !! I undid the plug, and whoooooosh... oil flew out in a big jet completely missing the bowl... it aint like a car !! Oh well, not my tarmac

Changed filter and Refilled with VX Oil - it seemed to take about 7 litres back up to the top of the stick, but I'll recheck after a bit.
Strangely, I couldn't find the fuel filter, though... I'll have another look shortly. I was going to change the ATF, but I have decided against this because the fluid looks nice and red. I'm just going to give it a top up instead.
I am pleased the engine is now running sweet, but there are just a couple of other issues I noticed:
1) Drivers footwell carpet is wet. I have had a good look under the car and can't see any corrosion, so hopefully it will be door seal. I notice the bottom one is a little split. I'll pull the carpet up for a better look in a tick.
2) small PAS leak. There is a small PAS fluid leak under the car, I saw a red drip on one of the pipes. The level isn't going down so V minor, and if it doesn't get any worse I will just clean it up for the MOT

3) Small amount of corrosion on the NS inner wing, it's a small localised patch, so I may have to talk nicely to anyone with a welder

All in all though - coming on!