After finding >>>/patriotsfight/62.html still up by going to it directly (and archiving it at https://archive.fo/dbWn6), I checked to see if there were any other hidden pages. I didn't find more than what is know, but I didn't check above 1000.
> for i in seq 1 1000; do wget https://8ch.net/patriotsfight/res/$i.html > /dev/null 2>&1 && echo found page $i.html; done
> found page 62.html
> found page 440.html