Now my wastegate has turned up and I can see what angle I need the pipe inserting at, I'm having a problem getting the hole machined. None of the machine shops round here have a 45mm slot drill (unsurprisingly), cnc time is expensive and will take ages as no-one has any spare capacity.

For the cost of the machining I could buy a slot drill and have access to several different mills. At this rate I could just buy a cheap stainless manifold!