So my enormous exhaust silencer arrived earlier this week. So I've spent most of this week's evenings messing around with sketchup trying to learn how to use it and figure out an exhaust. It's been a really useful exercise.
Worked out I need only two bends of 90˚ and around 115˚ or 65˚ depending on how you look at it!
Exhaust seems well made too, and it bloody should be at the price!