Hi Chris -
Indeed the plate is different. For WRS - you would need a different plate than the WDS - the plates for the WDS that fit into the mount are similar sized to the WRS plates, but as noted, have the notches that distinguish it from the WRS plate and and prevent it from mounting to the WRS.
On the good side - the Cambo Lenspanels are compatible, so any lens fitting the WDS will also mount into the WRS. That goes for most accessories, although some, like the new Rotating Compendium Shade, will be limited working with the WDS, due to the rise/fall action of the lens (on the WRS, the digital back performs all movements, the lens remains stationary).
We have them in stock.
Steve Hendrix