Eh, they were definitely from Xerox (so it would be unclear since that both Windows and the Mac System Software derived some of their UI elements from Xerox experiments)

The Alto? I don't think that's accurate. Only 2000 devices ever shipped, and I used one at my parent's workplace back in the day. But I would have been far too young to remember that detail.

It may well have been kicking around PARC before Jobs made the deal with Xerox. But I can't find any images that show either of those UI elements, pre-Lisa.