There was a member with the same problem many years ago...what he found eventually was that the leaf spring like tensioner arm on the points set was in the wrong place and wasnt providing the correct tension on the points...basically it was on tghe wrong side of the mounting bracket and that was enough to keep the pressure down enough that as the load got higher, the points werent keeping up.
In the following image, it is the flat metal plate that runs from the points past the arrow of #3 to the mount bolt that is in the line to the #4 arrow....hopefully that is clear...
Lord send your Holy Ghost into our hearts and make the desire of our hearts Your Will.
Pro-choice, that's a LIE, babies don't choose to die!!