Hey, I'll take any SM57s you want to get rid of - they're not the best mic for everything, but positioned right on the right amp, well, they're a classic for a reason.
I have a RSM-4 - it sounds awesome for leads on my Rectoverb, but on my Roadster a SM57 about 30 degrees off axis seems to be producing a better lead sound. The roadster's way darker than the ROV, though, especially on the third (of four) channel.