Currently building exterior corners with either clips, magnets, or any stand-alone 2" wall pieces results in a empty corner where the wall would meet. I have purchased and use the Printable Scenery Walls, but slice off the bottoms and use OpenLock bases. It would be nice to bases for the "C" walls. I said Cut Stone, but only because that seems to be the most complete set - why not keep building it out? But I don't really care what the bases are. Thanks!