After a so called professional magneto rebuild, my TS wouldn't start when hot ...I was then put onto a chap based in SE Queensland who identified that the secondary windings were breaking down and fixed the problem. He has since rebuilt several Duggie and Triumph maggies for me, plus a car starter motor and dynamo, all to a very high standard and at reasonable prices.
His workshop is an antiques roadshow of equipment as he has the old machines capable of handling the very thin secondary windings cable you find in vintage bike maggies..modern machines tend to snap these windings as they can't maintain the delicate loading/tension required.
Name is Ivan Brown ..07 5525 3707 and he lives in Tallai, just behind Burleigh Waters.
Hope this helps some poor stranded bikie !!