A final word, Armours were really good and refunded all my purchase cost, despite the purchase being 3 months ago. Feked sent me pipes with the assurance that they would refund, theirs have gone back too but I have yet to hear from them. Burton Bike Bits had the best fitting new pipes which I have fitted to the bike even though there is a slight silencer touch. I had to adjust the brackets by twisting and unbending them a bit, and putting 1/2" spacers under them.
Josef will be taking the old BSA pipes back with him to Germany, just in case he likes them better. They fit like a glove, but are a bit the worse for wear. S+T were happy to rework them but it would have been expensive (over £200 just for replating). They could also fill the dents with braze before chroming, but that would make it even dearer and they say there is a risk that porosity in the braze can show up as pitting in the chromed surface. Also (my observation) the BSA pipes are made from much lighter gauge material so I think they would be more susceptible to blueing.
I've learned a bit along the way, the pipes have been on and off the bike so many times I can say I know the differences in some detail - enough to confirm that they were made and mastered by different people. But I have not got to the bottom of why they all change the drop from one sweeping curve to two curves and a straight bit. I have spoken to all three firms in some detail but have not been able to speak with the people who make the jigs.
If anyone wants to know more detail I am happy to share on a personal basis, but I dont want to expose it in open forum.