Need help identifying what gearing system goes on this vintage Torpado

[stephen_torpado]

the downtube boss does look round in shape more like the french versions, this torpado appears to be like a collaborative hybrid between torpado and simplex

 

[stephen_torpado]

Does anyone know if the braze on boss i have on my downtube is compatible with a campagnolo shifter?
or is the circular shape more for a simplex or huret shifter?

 

[Big Block]

A bar end shifter may be used to operate the front derailleur.