Ernie, I had a similar issue with a brick mason that was building a firepace surround, where the panel was to fit between two brick columns.

It didn't matter to him that the Pioneer PDP was such and such wide, it only mattered that the brick was such and such wide.

He started laying the brick the way HE wanted and not what was needed.

Builder had to get involved and instruct him to set the brick in whatever manner it took to have the panel fit (in not so nice terms).

Turned out fine, but it was a battle time after time.