I thought I would go back a bit to see what the old timers called it. I dug out my copy of Frank Paine's Practical Woodturner, published in 1957!
I looked in the index and he doe not mention it. He does however list the 1/2" and 1/4" square and refers to them as 'long and strong' Unfortunately no mention on how to use it.
I got mine (a bit later than 1957) from Peter Child along with some advice from Chris Childs, mainly about sharpening and use. It is basically used as a variant of a skew
Ron