Add my name to the list of those that say you shouldn't hack anything off. Marinoni has to be one of, if not the, most prestigious brand in this country, so I feel like modding it would be a real loss.
Cynikal: Damn nice bike you've got there. A red SLX Marinoni in 55cm is my dream frame. Goddam. If that's a 55 and you ever need to get rid of it...