Facts are simple: Document is presented in a legal setting as unaltered from the date it was signed in 1989.
White-Out/Liquid Paper was used on two relatively long (and I be you guessed important) sections and then ink was used to write upon the White Out to conclude the change.
This document and one just like it were put in a safe (not hermetically sealed) and sat for 25+ years. Remarkeably they were then found and produced in pristine condition.
I have to call BS on this since the Current MSDSs list Liquid Paper as containing titanium dioxide, solvent naphtha, mineral spirits, resins, dispersant, and fragrances. **The organic solvent 1,1,1-trichloroethane was used as a thinner until 1989 believe it or not and I don't think these people were on the list to get the new stuff first. So it likely had the 1-trichlo, but even if it didn't, I have a hard time believing that it wouldn't eat the paper, or the ink or vice versa.
Besides the producers confessing, any scientific way I call BS and no time for a long lab wait for whatever results.