None are histrix and none are true flower rays.
Because there are very few rays coming out of Brazil, I am going to assume that these are Peruvian. that being said, I think that they are Orbignyi. They could also be Dumerelli but who the hell can tell the difference anyway.
Orbignyi are really neat looking little rays. I am also under the impression that they stay rather small (as far as rays go). They have cool patterns with some nice spotting around the outside of the disc.
Edit - the first picture is classic orbignyi. The last picture is a little washed out. See if you can get better pictures in a few days when they darken up on a substrate.
Good luck with the sale.
Colin