OK. Time to set the record straight. IMO, the coin in the eBay listing is not a 25th Anniversary "Set" coin but a 25th Anniversary Slab SAE that PCGS offered as a slabbing option for its Authorize Dealers. coins from the Set actually have the word "SET" in the slab label. No comment on the doubling other than not all doubled dies are of the same degree as the 55/55 or 72/72 Lincolns. Some do not have clear separation and show up as "thickened" lettering due to similar hubbing pressures. See the 1970-S DDO-004 on this page: http://www.varietyvista.com/Variety Master Listings/kennedy doubled dies 1967-1970.htm#_1970-S
Good point about the word "set" not being on that coin. I didn't even notice that since he had the auction labeled as though it were part of the "set". Thank you for pointing that out.