ok. here we go. All measurements are from the back of the upturned piece to the front of the piece that hangs over the bench- that is the protrusion of the tool.
http://www.woodturnerscatalog.com/p/95/ ... -Angle-Set
35 degrees, 112mm
40 degrees, 84mm
45 degrees, 62mm
50 degrees, 44mm
the gauge is about £11 from sorby, and in their defence it is very well made- angle sizes laser cut and heavy gauge steel. But i do not understand why they dont make the sizes available when you do need them. it is one of the few improvements i would make to the machine.
If making one, a few stop blocks on a bench hook would be ideal. you could put a line on a bench, but a stop is better, so you can butt the end of the gouge against it.