1968 Lincoln With Wide AM Due To Die Wear?

Quite observant! Die polishing is this cause with the residue filling the devices. There is two effects happening. Die flow, metal moving outwards and stretching occurring. Now, look at 2nd pic, the upper bar of the E. Note it is skinnier. This is because the face of the die has been worn down to make the rounded bevel near the edge. The device has become shallower(reversed image remember). New dies, when first cut, the devices are angle cut into the die, deepest is thin, becoming thicker towards the die face. Hope that makes sense, I have some diagrams I'll look for and post.

You are asking great questions so Crazy can go nuts, and the rest of us can shake our heads up and down, pretending we knew all that already