Varminter;
Ive been building box calls for a few years now.....after much trial and error im finally geting what i want out of them.
I havent really dove into the depths of friction calls yet but plan to build a couple this year.
a good source for slate (if your looking to start a project) is Dollywood there is a guy there with a regular stand who sells slate from old slate roofed buildings....they paint pictures and stuff on it. But he will cut peices any size you want. sells it cheap....or atleast he use to.
TCB