The repair is so excellent Dave Whalen cant see it with his own eyes either.

IMO xray will reveal the following:

A solid circle, beneath the inlay, where the clay used to fill the drill hole was removed and replaced by something else.

A faint outline of a circle where the drill hole was, as the clay surface of the inside edge of the drill hole would not have reached molten point through the full depth of the chip.

If I am wrong, the problem is far more serious than we thought. On other occasions, the clay used to fill the hole may have been taken from another chip.