Yes I think that you are correct, the hue is yellowish, thus brass. I guess most bodies are brass. I just assumed that metal would have been cheaper to market.
resummerfield: I am 'touching up'. You know: when the body starts to get that 'used' look I want to brighten it up. I still do not know if gloss, semi-gloss, or matte are best.
Not all are brass, many are now "resin" including some of the more expensive. There are also some that use cast aluminum alloy or something similar.
The gun finish is recommended by many as being durable.
Personally, I love the look of brassy cameras. Real photographers have brassy cameras, not minty-looking shelf queens. Some posers here in Tokyo actually use fine sandpaper to rub the paint off the edges and corners of their cameras. My old Leica M4 has been used so much that I managed to rub off the chrome finish on much of the camera. I had it stripped and repainted black last year, but it is already starting to get beautifully brassy again...