Chris Kovacs posted this in a comment in the 9 Princes thread, but I don't know if everyone reads the comments, so I'm going to give it its own post here.
There's an interesting photo from a 1980s convention that shows a group of fans dressed up as the various characters from the Amber novels. It's at:
If you scroll down among the comments, you'll see that participants in the photo have posted messages explain who is who. Corwin and Deirdre and side-by-side in the back right, and unfortunately Benedict is missing from the photo, having been cut off beside Deirdre.
Thanks for the tip!