How to identify a non lockup A999 transmission with pics!

I have 2 V8 904's, one is a 72 and the other a 73 so they were both made before the inception of the 998/999, and they both have the ribbing over the rear servo so apparently that's not an indicator of it being a 998/999. My guess is Gaz is right about it being there because of the double wrap band.