It would seem to me anybody with a copy of the SoH (1835, not 1834, is usually the date cited; a later reprint would work as well, and many libraries have such) and a scanner ought to be able to make new files that would work in place of the damaged ones. Or somebody who knows their GIFs might be able to turn the damaged ones into text files, spot and fix the damage, and reGIF 'em.

Liland