hand built , not really, they make use of extensive jigs and tooling.
just not fully automated..
In fact they de skilled the hinge to tube connection job.
and added finishing job, boring the holes in the Cast hinge,
that lends itself to a torch array jig.. for the brazing.

Where they had to train people to make a quality filled braze bead
with torch and filler wire, to join the Forged hinge-plate to the tube.

the forged hinge plates are lighter than the cast ones, FWIW..

one thing the Brake levers have adapted towards,
is having the cable pull in the shortest path,
towards using the shortest cable and housing ,
by angling where the lever meets the cable.
improving braking in small increments ..

But tinkerers will bodge..