Locating exhaust exit through side panel

[Alaskossie]

For the USA7a archives, here is a series of six photos showing a quick and accurate way to solve the three-dimensional puzzle of locating the body-side opening for the exhaust header exit on a LSIS, as performed by old Caterham hand Nathan Down.

 

The rule seems to be: measure twice (or more), cut once, enlarge incrementally.