I have an X3 on my list of mods to do. It's in pieces on my desk as I type this. I removed the bulb from the reflector already and I *think* that reflector might work pretty good with a Seoul P4. It looks nice. It is 30mm in diameter, and has a MOP surface.
I plan on getting one of those new upgraded Seoul's from Fred, an SOB1000 for it, and run it off 3 AW RCR123's.
Greg