It doesn't have to be exactly to the book, there are other ways to make it without the compound angles as long as it's up the job...a simple loop in round tube like the rear boot section does the trick....:)

I ended up tacking sw3 to the tranny tunnel then tack sw2 onto sw3 rather than assemble sw1-3 flat on the board then try to fit. It worked much better as it let me make sw1 to fit which ended up being about 10mm longer than the book spec and still maintain the 71 degree angle on both sw1 and sw3. Hardly had to file the compound angle on sw1 this way as well :)