Dre_j, I checked the data included by my Ruby 3s. The technical paper (aka 'specification' Ruby3) mentioned by stylus: nude line -contact diamond,mirror polished ,tip radius :5x120um. But on my, what you call 'frequency response sheet', the abbreviation 'FG-S' is writen by the stylus (kind).
I assume that the 'technical paper' is the old one (Ruby 3
without sufix S). I also assume that 'FG-S' means Geiger II
because this stylus is already in production for some time. Designed by Geiger and Van den Hul if I am well informed. By the mentioned Dutch retip service the prices are: rebuld Shibata 179 Euro, nude contact line 195 Euro and Geiger diamnod 265 Euro. The micro-ridge stylus is not offered so I have no idea about the price difference with the Geiger.
Regards,