One little thing that I already knew, but was made so much more clear is that my workbench is not much good at holding stock to be worked with hand tools. I hope to demote that bench to Assembly Table later this year.
But I was pleasantly surprised with this little solution at holding stock for planing. It really takes very little. In the photo the board being planed is not held directly at all. It is just pushed against the board that is held down by the most excellent Gramercy Tools holdfast. The near end of that thin board is pushed against the piece of ash in the vise.