Hi Christoph, thanks for your comment. There are some T65 corresponding to the different versions of the FeTAp 61. But there were no T65s with a Schauzeichen, so no 616 and cost counters were only used as separate items by PTT, so no built in versions like on the FeTAp 611 GbAnz.
There were several sort of RüAp equivalents, like the T65 Drieling (triplet) and the SE 5.
See for more info on the various variants of the T65 http://www.matilo.eu/3-the-phones/1960-1975-plastictijdperk/ptt-t65/?lang=en
Very nice article! Thanks for sharing. I am a T65 fan, I have the orange, gray, red, green, and ivory variants. There are also variants of some of the colors, like a black or colored “ground button”, I guess it depends on the year. I grew up in Argentina and we had the Argentinian version of the FeTAp 61, manufactured in Argentina by C.E.S.A. (Compañía Standard Electric Argentina), the later ones also had a “SIEMENS” brand on the label, which I guess is how it was licensed.