Ibanez Rules is the best place I've ever found for that kind of thing, but they may know exactly what you're talking about, or you may have to do some detective work to figure out the size and pitch of the threads. I mean, they probably have the exact thing you need, but you'll have to describe it carefully:
http://www.ibanezrules.com/parts.htm
Does the PRS SE use metric or English dimensions? For that matter, I don't know what the U.S. PRS's use... you can either start from the top-down, e-mail the manufacturer and ask, or from the bottom-up, take a post to a really good hardware store, ask for the "screw guy", and find a matching nut that'll tell you what threads to ask for from the Ibanez Rules dude, Ebay, Allparts....
http://www.allparts.com/Guitar-Parts-s/225.htm
http://guitarpartsresource.com/guitar_index.htm
http://www.guitarelectronics.com/c=1D30pK9DT91K7jjeETutDElSa/
If you think of it as a Mystical Quest it may not seem as sucky. :cool01:
