Very interesting MacMacV2 wrote: ↑Wed Jun 17, 2020 8:08 am Back in the day when I worked for MCN in the advertising office (very breifly...), I went to vist Peter Gibson.
Intresting method to make them. Shapes were cut from flat sheets, two bits, welded together one had an adapter welded on to it. This was then conected to a high preasure water pump. This when fired up it blew the pipes into shape... Trim off the ends & you have a perfectly shaped exhaust, expasion chamber & all. Shape the end to fit the flange, fit the end can & ring a ding ding...

Chris.