I better check properly tonight when I get home... with the 2 sizes of 7/8 and 1" I meant the quill size, so I am indeed thoroughly confusing not only you but myself also.

The riser with its 1-1/8" diameter sits on top of the threaded nut. So the steerer bit that sticks up is 1" in diameter. I can't say right now if it steps or not, I thought not, but I will check for you.