1974 50c O Seems Off Is This Normal?

I'm bumping this into the appropriate forum for better opinions. Looks to me like a strike artifact - you can see similar thickening in other letters.

Idle question, coop: are Modern dies basined?

In the Classic age, dies were polished to a slight bowl-shaped concavity to aid the strike process. Improper basining - this process - occasionally led to some odd artifacting at the periphery of the resulting coins (and to the weak centers of lightly-struck coins). I could conceive of an effect similar to what's being shown here resulting from two improperly-basined dies being slightly too far apart at the peripheral lettering, although the difference would have to be a dramatic transition to cause the "perspective" effect of these letters.