Tile 19 in the 512x512 pack is not 512x512, it's 600x600, I found this out by trying to import it into unreal engine 1 unrealEd which only accepts power of 2 textures and it gave me a weird bug where the import progress bar was stuck on the screen and I was trying to figure out why, turns out it's because it isn't 512x512 so it didn't import correctly :/ idk if you are still willing to update this but maybe you could fix that? It might be erroneously sized in the other packs as well I havent checked yet