I have purchased and installed the Rockford Ball Screw Series one retro kit on my Series I. You might try calling them to see if they can help you out on the series two. Tjhey'll be more help than McMaster. The McMaster kit is for a series one too at least that's what it looks like. I was just looking at a Series II, whole 'nother ball game.
http://www.rockfordballscrew.com/pbrkits.htm
Hope that helps.