The coin looks nice for almost 50 years old but the I is missing.I collect Radar dollars and I don't collect pennies so I don't know what to call this or if its rare but I've never seen one. Thanks, Matt.
Could be a grease filled die however the picture is to small to make an accurate guess. try to post bigger pictures if you can.
More than you'd like. Makes for interesting coins but not much premium value added. Because the dies are a negative to the coin's positive image, that means the "devices" are incused and sometimes gets clogged with gunk (grease, debris etc.) and that prevents the particular letter(s) or a portion of the image from being struck.