Not uncommon for a clay composition (Paulson-type or other) to warp in heat such as in sunlight or in their own box of 100 or less and, even take on a flat edge on the circumference edge where its own weight causes it. The interesting part is when found in quantity, that flat area runs tho whole length of the stack that was in contact with the bottom of the inside of the box where there can also be a bleed. The heat can and does also cause the protective layer over litho inlays of older chips to lift and the die-cut inlays to completely pop with the slightest movement since we have seen very little concave/convex action in many cases... but, the most interesting I have seen were the Die-cut metal inlays on the Tahoe Village $5 chips that someone tried to tap back in place (Newhouse Find archived threa) and the more recent boxes of the RED KC Coventry found without inlays.

Though not sure how an attempted repair looks on a clay chip but, the attempt on plastic laminated leaves a trail a mile wide; especially around the lunettes and pigment movement of softened graphics under the surface and the evidence of a roller such as a wine bottle.