I measured my late model Norris A-5 last night.  My technique was to take
an adjustable carpenter's square, one with a 45 degree angle built into
the handle, align the handle on the sole, and sight along the blade.

It looks to be a dead-on 45 degrees.  Has anyone  wondered, given the
fact that the iron rests on a wooden bed, if the company didn't care if the
angle of the cutter was off a degree or two?  Maybe the tolerances for
the bedding angle weren't all that precise.

Randy