ColonelHardisson said:
The vambrace does, indeed, strongly imply plate armor. Why would he be wearing plate arm bracers, and the rest be chain? It's certainly possible, I admit. I've admitted plenty of times that my interpretation of things may not be what Tolkien meant or what others envision. I don't try to make definitive statements about something that I didn't write; I only try to point out possibilities for others to use. If you don't want plate mail/armor in your vision of Middle Earth, cool; it's in mine, and it could be in that of others. There are instances where such a thing could be justified, and trying to definitively prove or disprove it just isn't possible. It's about gaming possibilities, not about who is right.
You're right, it isn't about who is right, but in this case you're not.
Tolkien was
very clear about what "age" of history/mythology he was trying to emulate -- the heyday of the "Heroic" germanic tradition. And during that time period, full plate knights, or even plate armored knights as seen in the movies, are completely absent. That is actually not too difficult to prove at all; I don't know why you want to insist that it cannot be.
And vambraces, greaves, and all kinds of other "plate armor" items predate the full plate knight regalia by literally thousands of years, so I don't know why you insist that they must imply plate armor. Heck, the Bronze Age greeks who sacked Troy, assuming their was a historical sacking of Troy that served as the kernel of the legend, were wearing vambraces and greaves in 1250 B.C.
But clearly, it's not something that Tolkien was very clear about
in the actual text of the books and contrary to all the fans that were in an uproar over the "knights of Gondor" that Peter Jackson put on the screen, I honestly don't think its that big of a deal. In fact, Tolkien
might have been amused to see his creation take on a life of its own like this, not unlike the mythology on which he modelled it, which always seemed to reflect more the world of the scribe who wrote it down than the original sources which created it.