Just resurrected an old Proflex 856 frame, and I am having an issue with how to run the front derailleur cable. It almost seems as some sort of cable guide is missing at a point where the cable travels through the rear swing arm mount point of the frame. The cable runs through the normal looking cable guide under the BB, and through this hole (currently bare cable) to the FD. The problem is that the cable rubs against the edge of it. Soooo I am wondering if its just a simple case of an incompatible derailleur, or a missing piece of the frame...

PS: I can think of several ways to jerry rig something up, I just want to know if there is a legit solution before doing so.