It looks like it just may be a planchet issue. Not all planchets are created equal, and some of them may show a graininess or almost "wood texture" during the sheeting process. The planchet is then struck, and I agree, probably by a die that was well worn and the end result is what you see.
As a die gets clogged with debris from other strikes, the mint workers usually attempt to clean out some of the debris so the strikes will be clearer and the die gets a longer life. Scratches are quite common, especially in the 1950's-1970's.
Check the mint mark with a Loupe or a microscope, the mint mark may have a "d" over 'd" as described above. typically a good D/D (aka RPM - repuched mint mark) will show a spilt serif, or two distinct points on the top or bottom, or both - of the D, much like the picture shown above.
www.coppercoins.com is a great resource to look for specifics errors and varieties. The "markers" are things that are found on a coin that was struck by the same die. So, a d/d coin may show a die blob, scratches or other things in a particular location. Markers are not always there, due to light or too heavy a strike, or the "age" of the die - which can eventually change the markers as well. Coppercoins has links below a particular year / variety that may show EDS (early die state) MDS (medium die state) or LDS (late die state). usually the EDS versions seems to hold a slightly higher value than the others states.