Looks like a Florida gar to me.
Keep in mind that 99% of the "spotted gars" and "Florida spotted gars" out there are just mislabeled Florida gars. There's also a tremendous amount of variability in their pattens & coloration, so just because it doesn't look exactly like other Florida gars that you have seen doesn't mean that it isn't one. There's also probably some stunting going on with it considering the previous atrocious conditions that it endured.
P.S.-- Ditch the pleco ASAP. They have been known to suck on gars' slime coats which often leads to a deadly infection; all it takes is one incident while you're not looking, and you gar could be done for.