Ah okay, thought it was something you added on or brazed on yourself...
I have a similar frame with a 'clamp on downtube shifter mount' and was looking for a neat solution to be able to use brifters
I can't find a link, but I have seen bikes with a collar housing twin cable stops that fits between the lower race of the headset and the frame. It's very neat.. but also apparently rare :-(
Ah okay, thought it was something you added on or brazed on yourself...
I have a similar frame with a 'clamp on downtube shifter mount' and was looking for a neat solution to be able to use brifters