Will you be drilling them and gluing a brass tube for a kit into them?
If so, drill for the tube, then square the ends that will be glued together (I'd do it with a sanding jig that holds the blank by the drilled hole, because you can't trust the outside walls of the blank to be perfectly true). As you glue the two half-blanks onto the tube, just put a little glue on the faces that are going to mate up.
I use 2-part epoxy, had a couple of bad experiences with CA for gluing tubes into blanks.