I am selling off some illegals on (mostly dupes and extras) and I know that if I clean the chips before I list them I seem to do much better dollar wise BUT I just don't have the heart to clean an old historic chip like this. I feel that the grime on the chip adds to the history but some people will just say "YUCK." It looks like there might be a little yellow left from the stamp but... To Clean OR Not to Clean... That is the question?
The chip is listed here--> http://www.ebay.com/sch/tucsonsmitty/m.html?item=310632349048&ssPageName=STRK%3AMESELX%3AIT&rt=nc&_trksid=p2047675.l2562