In the book at page 46-925 is described the Distagon 2.8/35 and in the description is written 5 lenses in 5 group, but in the drawing of the lens there are 6 lenses, like the Contax version.
Thank to the fuwen site I have found the correct drawing of the Distagon in the Rollei version http://www.fuwen.net/index.php?option=c ... &Itemid=88 in the picture linked the lenses are 5 like described by Mr. Prochnow and like described in various instruction manual of the SL camera.
Ciao