Ok here ya go...I actually just completed a similar project and if I get motivated I may post pictures.
You will need the following to attach to the ball lock:
1/4" Flare Swivel (I could only find this at Ace Hardware. My local HD and Lowes did not have this part)
1/4" Male Flare x 1/4" MIP
1/4" Brass Tee - Don't forget the teflon tape for good seals, and most people swear that no tape should be used on the flare fittings, your choice.
and if you are building a keg pressure tester add in a pressure gauge, lower psi probably and a 1/4" valve.
Construction: Screw Male flare into swivel, MIP side into tee, and attach ball lock to other side of swivel.