What model of Dolomite are you running? The Sprint, with it's unique-to-model 44D4 distributor, seems to be allergic to any sort of EI except the most expensive, Lumenition Optronic or the even more pricey and complex to install 123 programmable distributor. Magnetronics seem to last a few weeks at best and if you are lucky enough to find a NOS Accuspark kit, you'll be even luckier if you can get it work at all! Accuspark appear to have withdrawn the Sprint kit BECAUSE it's failure rate was too high. Though I gather they are now offering an older style "points assisted" system with an external amplifier block, similar to the Piranha systems of the 70s with an Austin Ambassador style distributor cap and leads.
I used one of those cheap britpart ignition modules on my Sprint engine, with an Ambassador cap and a cheap 12 volt generic coil. It seems to work fine and my experience with the 1500 is the britpart module seems pretty bullet proof.
The key to making it work on a Sprint, SEEMS to be the employment of the taller Ambassador distributor cap and rotor. I have here an early ish Sprint kit which looks like Accuspark, or possibly Britpart. I'm not sure of it's ancestry, as I found it, new and boxed, in the boot of a car I bought! However, the point is, that I tried to fit it to the car with the failed Magnetronic, ( the replacement dizzy, not the knackered original) only to discover that the rotor arm (supplied with the kit and slightly thinner than a genuine Lucas one) still fouled the top of the pickup/module! Noting this, I didn't try to run the car with it and put the points in instead! But I may get an Ambassador cap and matching rotor and leads and try it on some future project!