Wow that was a nice hunt. That's what I love south of the border, there isn't much competition while hunting.
Cleaning the coins might help. I know how picky they are, they won't accept a dirty coin, but will accept a coin that is almost completely worn down or paper money that so delicate that it could rip into pieces just blowing on it. I know one just has to accept it that way.
Post more finds as they come.
Thanks.