Mike,
In my case, I've not actually setup the tanks and bombs to fly with them. In the picture, the tank is held with magnets to the sway braces purely for placing them on the airplane on the ground only. That being said, you can simply place them onto the pylons for flight using two servo screws (ones with integrated washers) on the pylons and key holes in the stores. The screws are screwed into the bottom on the pylon hanging down. Depending on whether you have the scale openings like I do or not may require gluing in some balsa blocks for the screws first. Then, using a dremel and a small 1/16" cutter bit, dremel a couple small keyholes into the stores at the appropriate locations to match up with the screws. The orientation of the keyholes should be such that you slip the store on and then back (to the rear of the airplane) to lock it in place. It's a friction fit and you can adjust the pylon screw lengths to the desired length for the amount of friction. Hopefully that made sense? It's a really simple and effective way for placing stores on our airplanes. I've been flying the wing tanks on my mirage like this for years.
Chris