Scott your call looks great. The trick to these is getting the surface conditioned. The first time I made one, I put the face of the agate on my belt sander with a 60 grit belt, it literally polished the agate. That's when I new I was in trouble. Some try the acid etch cream that you use on glass. I tried that once, after 20-25 treatments it still wasn't even close.Need some kind of diamond roughing stone. Will your guy be interested in selling to others if he can get them to 1/8th thick. Buying them in coaster form gives you a variance in the thickness, some are 1/8th, some are thicker, but you can get them for around 4-6$ each.
"Instruments of Mass Destruction"