HeelSpur, when you had the valve in the Duro, was the head of the valve against the thumbscrew on the left in the 1at picture ?
I believe you are correct in calling it a valve refacer. the top of the valve would touch the thumbscrew, and the large plate with the
locating pin would sit on the stem, but not tight. then there would be a short handle that would be attached to the end of the stem
sticking out. the short block should have a cutter in it that you could set the angle to recut the valve face by turning the handle.
I have a couple of these, if I can find them, I know that one is missing the handle.
look in the box for a short handle with a set screw in it.
this is what makes me think that is what you have.