Kirk, it was not unusual for Ford 1172 motors to be supercharged when the blower was readily available from places like Valentines in Hamilton. They and others were sellers of war surplus items into at least the mid 60s and stuff was cheap.
Just because it's a supercharged 1172 doesn't mean it had potential. There were some well built specials, some not so. I am NOT saying where this one fits, as I do not know.
As usual don't take too much credence of the book you are quoting. It's a resource but pretty much everything needs checking elsewhere.