I had decided to pass on it, but your comments have cheered me up towards buying it...
The amp is in Rio de Janeiro, I'm from Brazil, so it was on a humid setting probably. Can't test it as I'm in Sao Paulo. Also, it hasn't been used for a long time, and I would be buying it from a retailer, actually distributor of some high end brands (not Bryston though). I could remove the screws and paint them, but I'm worried the humid climate might have gone inside the amp and messed some things. I had problems buying used already (plenty).
The seller claims it is fine, but who knows, it's actually dirty cheap, the last I saw locally went for about 80% higher (this one is for about 1250 U$, last I saw was 2100 U$).. Seller claims he got it as a trade in and just want to see some cash on what he got it for.
BTW, there is no warranty on this and the rust is real, I mean, it's actual red all over most of the top screws.