Some would have made the plates up/down because it's easier! I don't think just washers would do, the pedal force is pushing it off the bracket rather than against it?
Ah, but up and down wouldn't be much better than washers, needed to be across to simulate being a whole plate - or that's how my mind saw it.
Fits nicely and feels solid I've now connected everything back up and we have a good pedal. Can't start the engine yet so haven't tested the servo but pleased with the conversion.