i bought a bare 500 frame on ebay, built it up with some various campag bits, it was a beatiful ride. a chap in Slough bought the frame from me and has rebuilt it in shimano ax, it's absolutely beautiful with all the blue accents matching the frame colour.
i'm sure i was told it was a 1991 frame by someone on the raleigh bikes forum, it wasn't in the catalogue from 1990, which you've probably seen already - google raleigh dynatech 500 to find it as i'm not allowed to post a url or link yet!
richie