UFO caliper questions

[Rbade12@aol.com]

Are rebuild kits available for UFO calipers? What purpose does the thin  
steel rod a couple inches long with the small puck on the end, on the  back of the 
caliper serve?
 
I've got an extra set of calipers that I cleaned today. The 2 halves of the  
caliper seem to be prevented from coming apart by the rubber boot over the  
thicker of the 2 slider pins. I don't want to tear that boot [which seems to be  
a distinct possibility if I try to free it up] unless I can replace it.
 
A good source of UFO rotors? Anyone cyro treated UFO rotors?
 
Thank you!
 
Bob