Why didn't the mint modify the designs on the Standing Liberty quarter and the Buffalo nickel once it became obvious that the designs were faulty due to the dates wearing off? I have large cents from the 1830's that are AG. I can still read the dates though. Yet these quarters and nickels are much newer and they are often found dateless.
They certainly modified the SLQ, starting in 1925. They modified the Buffalo reverse after the first year to recess the mint mark, but for whatever reason didn't redesign the obverse. Well, I guess they did in 1938.
