All done,

I found a site on the web that said the ignition igniters are interchangeable.

I couldn't ascertain whether there was a spark or not because it was an intermittent problem.

Lifting up the carpet and looking at the ECU - after switching on the ignition - look through the viewing glass - only one flash - so no fault codes

I decided to take a chance and change it. 3 bolts around the distributor - take care not to strip threads WD-40.

Cap off - it was unbelievably dirty - may have contributed - I cleaned it and scraped the terminals carefully.

Ignition igniter is the small box with four wires coming out of it . Make a note of the wires - use a professional rubber handled screwdriver to avoid stripping the threads - WD-40 - remove the two retaining screws and the small screw holding the wires.

The old unit was an OKI - the one I replaced it with I think was a redesigned one by HITACHI - as this one was fitted by a Rover dealer from a previous car - hopefully this one won't break down.

Clean out the distributor with a brush and blow dirt out - reassemble and bingo - good as new.

A week before I noticed the fuel consumption drop by 10 mpg from the usual 38-39 around town, I put it down to the cold weather. It is much smoother now, so It was running roughly for a while. So symptoms are rough running , then missing beats, then cutting out then non start.

Hope this helps someone else - job took about 30-40mins