Also, The R No.2 -- the R probably stood for Rational (or Rationnelle) and looks to be an early model (a guess). The No.2 matches it with the Reporter Series (Series 2), but fine if used with the Series 3 Studex. It is not a particularily heavy-duty head (maybe holding up a Harley instead of a full-on aircraft). I used a Gitzo Ballhead No.2 for a long time with a lightweight 4x5 on my Studex Series 3 (plain, non-Performance).
The only drawback of the head I see is that it is rather tall and when combined with your camera, the camera sits pretty high up above the top of the tripod, which might cause some wobble/vibration that you just have to aware of and let the camera settle down before opening the shutter.