I've been thinking about changing out my brass hinge for a stainless one. I'm having trouble locating one the same size though, its got a 5mm pin, 57mm across when open. The join size is 25mm (an inch).
I found one a bit bigger here:
http://www.juststainless.co.uk/products/hinges.asp
Suppose it can't hurt too much as it will only make 0.5mm difference overall I guess