The cancan scene in GWTW lasts only a few seconds and is seen from the balcony, but courtesy of Dave DeCaro's Davelandweb.com you can see some stills from the film. The relevant page at his site is:
http://davelandweb.com/celebs/vivienleigh.html
You can also find a history of the Golden Horseshoe Saloon at Disneyland and a number of photos from that show at his site at:
http://davelandweb.com/goldenhorseshoe/
