Despite the differential in thickness, these keyboards look so similar that we're tempted to mix dark Magic with light and see what happens...

Yes, what you're looking at is a 2015 white Magic Keyboard keycap on a 16" MacBook Pro keyboard and scissor. It works!

The old Magic command key is smaller (hence the larger gap around the key) and thicker than the new one.

Not every single key is interchangeable, and the old Magic keys don't have transparent lettering for the backlight. So don't get too excited yet, keyboard modders.