Apparently can't link directly to the page. Try here and search the Mustang catalog for quarter panel. http://www.dynacorn.com/site/04home/home.html
I don't know if they have been released yet, but I am sure your local mustang parts house can find out.
It looks like this for coupe/ convert.
It even looks like they have done this for 71' and 72'. The number of parts they have reproed since releasing the full floors is astounding. I think they are hellbent on reproducing almost every 60's muscle car ever made.( 'cept maybe the AMC AMX...I really liked the looks of those too.)