Are you sure about the Unicomp keyboards with the one piece keys?
My customizer has 2 piece keys, they are grey. My spacesaver I ordered with black keys, they are one piece.
I prefer the 2 piece keys. Its probably all in my mind, but I think they add something to the feel.
I suppose the best way to find out, would be to weigh them. If they weigh the same then I would think its me. Does anyone have a scale that is sensitive enough to weigh the difference?