ferguson 35 tractor, missing when hot?

Is there a known problem with the ferguson 35 tractor, 4 cylinder petrol motor that causes it to miss when it gets hot. I spent a lot of money on repairs and parts only to have it keep happening. I think i eventually solved the problem by getting a distributor cap thats made in England. The ones made or supplied by Bare co in Australia seem to pack it in after a minimal ammount of work. I would like to know if this is a known fault as i figure bare co owes me a lot of money for repairs if this is the case as they should have recalled them. I am gathering what information i can before contacting them as i brought 3 caps before i found someone that suggested there was a problem with them.Also the cost of other things various people tried to no avail could have been averted if the caps had been recalled.