Hi Guys
My sincere apologies for not having replied sooner and for looking like I was an ingrate and wasting your valuable time and kindness. That is absolutely not the case, I assure you.
The thing is that this A is a daily driver and the cutoutalitis has been driving me absolutely crazy. I tried every fix you guys suggested and just when the problem looked liked it was gone, it resurfaced. Absolutely at random. So I didn't want to reply until I found what it was. And now I have.
It was the needle and seat. I replaced it and instantly felt a sweetness of engine speed and responsiveness. I can only conclude that because my A does high mileage, the steel "needle" (ball) eventually wore out the brass seat, and must have created a situation where for some reason it didn't release, starving the engine of gas (fuel... btw I having been using Shell V Power 95 unleaded for many years now... I figure the engine needs all the help it can get in the hectic Johannesburg traffic). Then, when the temperature cooled down (i.e. the five minutes waiting period) the ball must have released itself, providing fuel again... and then the process repeated itself. I am now 100% certain that the problem has been fixed because I put the new needle and seat in yesterday and did some serious highway work (i.e. under load) and the A has not missed a beat and is going like a Boeing.
So the lesson that I have learned from this is that no matter how experienced we become there is always something new to learn. The upside is that all the electrical connections are now **** and span, all the wiring is checked and solid, I have a spare coil and condenser and points on hand and I know that my ignition switch is hunky dory and I can now also remove and clean and replace my Zenith with the speed of a NASCAR mechanic.
I want to thank you guys for your amazing approach to helping a forlorn, desperate A owner on the other side of the world. America is truly a great country.
With warmest regards,
Chris Van