What I meant in my earlier post was that the appearance of exactly matching
mass-produced zither pins was counter to the image of a finely finished
hand-crafted and decorated instrument. Hand-made traditional pattern pins,
in contrast are subtly different to the eye, and 'fit' the atmosphere of the
rest of the instrument.
Regarding pianos. much of my work now is making sets of trad pattern pins
for restorers who are rescuing insenitively restored early pianos which have
modern square head pins in them.