If it is a rescue and not a shelter then could you suggest at least FF or Friskies? I know neither are great quality but they are wet. Doesn't catinfo.org say even the worse wet is better than the best dry? They are still a tiny step above the store brand kinds IMO.
If you can't I have found Taste of the Wild is one my kitties eat. You just have to watch the diarrhea as it is quite rich. I also use the Kirkland brand for supplemental feeding with the Catty Cats. As I have stated before in the winter they eat more dry as the wet freezes too fast. They may be mostly semi ferals but they are very well fed ones.
They don't always eat right away. Kirklands' first ingredient is chicken. I have not seen a new one at my Costco but that could be because it is still in testing and not available at all stores.