Not so, Paul. I have in hand a 2x3 RB Ser. B with Graflex back and four 2x3 Graphics with Graflok backs. I also have in hand an early Graflex 23 roll holder (Graflex, not Graphic, is painted on the back of the shell) that fits the RB and the Graphics. It fits 2x3 Graflex and 2x3 Graflok backs correctly. I also have Graphic 23 and 2x3 RH roll holders that fit my Graphics (all have Grafloks, remember) but not my Graflex RB and a late Graflex roll holder (Graflex on the back) that fits my Graflex RB but not my Graphics.
Originally Posted by paul ewins
As I wrote, there are exceptions and I have one. I wasn't speculating or quoting internet BS, I was reporting on what my gear does. BTW, Graflex Inc advertised early Graflex roll holders as fitting Graflex and Graflok backs.