The ThinkPad keyboard is using a .75 U Windows key, and 1 U Alts, FWIW, in the Windows key versions.
And, actually, my real ideal layout is .5 U narrower (.25 U taken out of the spacebar, .25 out of right Alt, and .5 out of backspace, \, Enter, and RShift). But that's not ISO-friendly, and even pulling .25 U out makes keycap availability that much harder.