It doesn't look like a Casanova outfit to me, (not if it's supposed to be the one he's holding, at least) the collar is all wrong, far too high, and I don't think the braiding on the front was anything like that in Casanova.

But not only is there a 4th Doctor scarf draped there, David is also wearing a (replica of) another 4th Doctor scarf. And I'm pretty sure I saw the fifth Doctor's hat, too.

There's also, in one of the shots in the wardrobe a brown leather suit with a white ruff collar that I'm fairly sure I've seen before. Somewhere. But I don't know where exactly.

XWA