WTB - 73+ Lower Control Arm Drivers side w/ Sway Tab

I have a single drivers side with tab, but believe it is a 68 unit. How doe you tell the difference?
I have been carrying this thing to swap meets for years, it is all glass beaded, painted an pretty!

The earlier design has the tab located very near the ball joint end of the arm. The later design has the tab closer to the center of the arm.