Clipper Cutting out Help needed

Hi

Have had this usual problem of cutting out whilst driving along it will also do this when warm and left idling on the drive for 5 mins will just suddenly fade and cut out, this has been going on and off for a year now will list below the jobs done.

1. new filler neck
2. tank drained twice and cleaned out
3. new filter sock on sender
4. new braided fuel hoses throughout
5. new clear glass fuel filter (is always full when it starts to cut out on idle)
6. new fuel pump
7. new fuel vaporiser
8. Just fitted new Weber Carb over the weekend and managed to do about 5 miles before breakdown.
9. new carb/manifold gasket

over the last 18 months had new plugs, dizzy cap,rotor arm, leads, air filter.

Have also checked that the flap in the airfilter is not seized and have by-passed the little heater on the airfilter housing but it will still cut out when not moving so I guess this rules out fuel icing . Have driven without the fuel cap on in case of  a vacuum. Have twisted and pulled at wires etc.. when running to find if there is any fault.

Could this be electrical ? I have not changed the coil, or the amplifier (not sure if thats what it is but just below the windscreen on the passengers side). but did  loosen off a ignition lead so could hear the spark and there still seemed to be a spark as it cut out.

My only other thought is the immobilizer ?

I am going to get new vacuum pipes and rubbers today as forgot to do these.

Any ideas would be greatly appreciated, I live in Stafford does anyone know of a MK1 specialist in this area ?