Jerry Moos said;
"The usual solution to this, as seen on my 1968 Tipo Roma, was that Legano tapped a hole into the back of the seatube near its top to mount a special brake hanger curved to match the tube curvature and secured to the tube by a bolt run through a hole in the hanger and threaded into the hole tappe d into the tube."
I have a 1961 Legnano in the same color scheme as the bike in question. Mine did not have a tapped hole. Instead it had a clamp- on stop about the seat post for the cable stop. With age, I wanted something a bit more secure so I replaced it with an almost identical piece: I called Joe Breeze when his Hite-Rite seatpost adjuster for MTBs came out as the mechanism by which it was held together was a very close dead ringer to the original Legnano part.
Ken Wehrenberg, Hermann, MO