How long do Ziehl-Neelsen stained samples keep?
This TB study might help you: external page
Briefly, they used 6 to 19 months old samples of mostly bad quality (due to their age). The last sentence of the quote below sounds promising though.

The 12,543 sputum smears stored at the national TB reference
laboratory for 6 to 19 months were stored at room temperature in a
wooden slide box without a cover slip. Most of them had lost their
stain reflecting the counterstaining with methylene blue. Restaining
of 436 doubtful slides by ZN gave disappointing results throughout [...]
After a 6 to 19 months storage of ZN stained sputum smears in a
non-air conditioned atmosphere, the bright red color of eggs due to
carbolfuchsin had virtually disappeared. [...] In such case, the ZN restaining of sputum smears allows to rediscover AFB that were discolored.

When I did this the last time, we used fresh and few months old samples which looked similar to the first of your images. Just have a look at the paper, I guess.