Let me just conclude this side point by mentioning that the correction seems of an additive nature rather than a substitutive one. An addition of ideograms seems therefore more likely than a change in inflexion. The main assumption I have made in the above is that the markings on the disk constitute some kind of writing. I am not sure this assumption is justified. The only two reasons I made this assumption are that, firstly, it seems unlikely that a set of imprinting tools would be fabricated if their markings served a decorative purpose only, and, secondly, the fact that the first mention of the disk included a phrase mentioning an undeciphered script.
Complete objectivity is often hard to maintain.