Some of them do fade into the background or appear extreme due to a lack of cameo frost though. The proof IKE is a different story though as these coins are peglegs by design, similar to the 1972-S Proof and 40% Business Strike coins which are all peglegs. Extreme cases have the leg of the R actually fading into the field. After a certain amount of die abrading and repair, those serifs invariably get polished off leaving that left leg straight up and down. To repeat, the R in LIBERTY on your typical Eisenhower Dollar has serifs on the left leg of that R. Here's a little post although it does not concentrate specifically on the 1971-S Pegleg Proof it does give some definition on what a pegleg is. It is kinda weird that the post went unanswered after a couple of years!
