The bead itself is called a staff bead,the V groove is called a quirk....as for attaching,the old way was to take a piece of timber slightly thicker then the brick joints,this was with your lathing hammer "axed" to a "propeller" shape.....and then pounded into the brick joint,the shape would twist as it was driven in and pretty well never come out....these were then cut off plumb,and the bead attached to these plugs.
Scratch and brown upto this bead and then "quirk" the bead (v groove) wider then the actual finished product,then skim into the bead filling the quirk,just prior to final set ,the quirk is cut out again (we used a small tool and feather edge) hold feather edge plumb to bead and cut out the skimming.....some areas referred to it as a "birds beak"