Nobby,
It was easier than I thought to get it stretched back into the way it shouldbe, as pictured above. I did think of doing it the way you mentioned but it would really be a difficult task to get the tighter bends into such a small isolated peice of sheet metal. Someone may prove me wrong, but this way worked for me! 17.5 litre now, yeryer!!

TBA, Stainless extractors / drag pipes, 65mm over forward controls, Thruxton needles, 904cc, head ported, lowered 1-inch, Console removed, relocated battery box, Australia.