I've got a question for an 80's Schwinn/Shimano expert out there. I have a 1984 Schwinn Super Sport that I'm trying to adapt for bar-end shifters. The current setup is downtube Shimano 600 shifters. I was told at my LBS that because of their thin profile these friction shifters were an 'aero' version. I bought a set of Shimano downtube cable stops, but when I removed the shifter levers, the boss' shape had a weird round base with a key shape(?) in it that points up the bar, toward the handlbars (see pictures below) The cable stop won't fit over the boss' base.
So my question is, are there downtube cable stops available that will fit this strange boss shape? I'd like to avoid the clamp-on type stops if I can. I could find very little in the forums other than these bosses are strange and sometimes called Italian style bosses.
Any help would be greatly appreciated.