Practical Life-Corn grinding

We found a pestle and mortar for grinding spices for $9.95 plus tax in a small shop this weekend. I can't wait to set up a corn grinding activity for the kids this week as we ease into Thanksgiving time and incorporate a few  American Indian activities. It is a solid white ceramic model which is just the right size for my 6 and 8 year old. I saw a miniature one in an antique shop across the street from where I bought this one for $18.00. It was smaller than a tea cup. It would've worked for spices but not the corn. I am also really looking for the nut cracker that is screw like not like a vise.  As soon as I order one from a Montessori catalog I know I will find a store with one.