Ahhh...FTS. No, I do not. The rest of the tank is empty so nothing of interest. I 'scape as the mood strikes me, usually after a glass of Bourbon.
Jonathan-You've stacked enough rocks to know that there are logical fits. I just exploit that. First, I find a rock from my holding tank that I want on the bottom, see how it looks from all possible orientations and then take a Dremmel with a flex-drive and a ceramic tile bit. I use that to start 3 pilot holes in a tripod arrangement. Next I use a 1/4" masonry bit in a regular old cordless drill to get good pilot holes. Finally, a 1/2" masonry bit to enlarge the holes. I "spot weld" the rods in the holes with West System 5-minute epoxy. Then I stand the rock on the rods and cut them to final length using the Dremmel. This way, the bottom of the base rock just touches the sand bed.
I do the stack rock basically the same way but they only get 1 long rod that goes through the lower rock clear the the bottom. I've only gone 3 rocks high and the 3rd rock only gets pinned to the second rock.
I use the Dremmel to carve out enough rock so they really "lock in" when the rods slide through.
Next time I do one, I'll try and get some detailed pictures.