The pizza stone and tray works for damper and pumpkin scones. I haven't tried cakes, but I reckon you could use the pizza stone with standard cake tins no problem.
And yes, the scones tasted as good as they looked, but a bit overdone. Flo Bjelke-Petersen's recipe, but my wife's grandmothers recipe (also a FNQer) is better, just can't find where the recipe is.
They were only in the Weber for about 25 minutes, but I reckon 20 minutes would have been enough.