Damn, I was looking for this suit for ages!
Yes, I see that most of these pictures are from books...
I don't think that it'd be greave... where'd you put that "metacarpal"-like plate? It's shaped rather oddly for a sabaton... and it's too short. If the author'd've mentioned something about this...
BTW, I found an interesting vambrace at rubens.anu.edu.au. It has that widening I missed before, and is quite like the one on the met suit, only that it's shorter. But if we take into consideration that it's made from 3 plates which couldn't compress, while the met one in made from stripes... Hm. And it's too high for a greave, and if I'm correct, the turkish armour fashion used m&p cuisses with mail demi-greaves, which'd cover about the third or half of the greave. So such a high greave would be a waste of metal and would needlessly increase the weight.
There's a quite simple way to get proof... I'm in need for a full eastern harness... so I think, as I have the picture of it now, I'll build THIS for myself at last. If the vambrace works, good, if not... then we're looking for very-very long legs...