So it appears that your instincts are correct, and whatever source
claimed it was a Reaming Iron was wrong. I doubt that there is a more
qualified expert resource than MMM. Hopefully, Mr Lipfert will find out
what it really is. Or at least, become a dedicated follower of your
"What is it?" website.

Thanks for checking on that, I'll be interested to see if he can find any
info on it. The seller of this tool also had another very similar one, the
only difference being that the head of it was about 1/4" thick instead of
1". Still too thick to be described as a chisel, yet it was also marked
reaming iron.

Rob