This page...:
http://originaltrilogy.com/forum/topic.cfm/The-NEW-official-Screenshots-thread/topic/4681/
...states that 5 fan made preservations are anamorphic.
But if you want the best preservation of Star Wars. I highly recommend OCPMovie's Classic Edition 2.0 Version:
http://originaltrilogy.com/forum/topic.cfm/Star-Wars-Classic-Edition-2-0-NEW-from-Ocpmovie/topic/6935
and the Lucasfilm Pwnage Edition:
http://originaltrilogy.com/forum/topic.cfm/Star-Wars-Classic-Edition-2-0-NEW-from-Ocpmovie/topic/6935
PaulisDead2221 is currently working on a Vintage edit which we don't know when it will be available:
http://originaltrilogy.com/forum/topic.cfm/Star-Wars-The-Vintage-Edit/topic/8069