Paul got a bargain on his Radian, but it was in need of a lot of TLC and restoration work.  After reading his email, I looked at the pictures and they immediately put a big grin on my face.  What an outstanding fantastic job!  He said he believes the tank is from an XJ550, and the seat is custom modified to accommodate the shape of the tank.  Other apparent mods are the straight bars, the bar end mirrors, and round headlight.  The photos are also HERE as a downloadable zip archive.  That's awesome, Paul!  Thanks!  ...and yep, this is the third Paul, and all three are in the U.K. :-)