I'm working with a part that I configured and downloaded from 3D Content Central.

The part contains a couple of Revolved Cuts.  I want to alter one of them, but when I select the sketch for editing, I am presented with a fully defined sketch that has no visible dimensions.  If I try to create a dimension, I'm prompted to make it driven, implying that a dimension already exists and that adding another would over-define.  However, the existing dimensions are not visible anywhere.

Anyone run across this before?

Cut-Revolve1 is the one I wish to alter.