Generally it should be easier to change a string with "bridge pins"
because: 1) you don't need the string cutoff for the small strings. A
knot is sufficient. (If you have the correct pin in a proper hole)
2) You can tie the knot on the outside and then insert the knot
through the sound board hole from the face, and avoid having to poke the
string throught the hole from the inside
However, please note that "bridge pins" require a much larger hole than
the string requires. This leaves the sound board weaker. I avoid these
pins when rebuilding soundboards when the owner will let me.
Perhaps much older harp builders made use of ivory (Mike P, can you give
dates) but I have yet to see ivory pins on an instrument from this
century.
How do I know? If you sand one of these pins it smells like a pingpong
ball (Celulose), not like a dentist office (bone), also they burn really
easily.
THe size used on guitars easially available. Smaller sizes are
impossible to buy, but you can have them turned out of wood,
bone, or brass.
Arsalaan Fay