Here's one that's listed on Ebay. Apparently PCGS uses D/S for "double struck" which is confusing. If any abbreviation was going to be used, they should just use DS. http://www.ebay.com/itm/1977-Double...Error-Rotated-D-S-in-Collar-C10-/160938860607
I got some pictures of the coin. I guess I was wrong on the grade, graded VF35 not 20. Sorry about the poor picture quality but I only had a few minutes.