Carey Beebe replacing a bent gap spacer on a harpsichord in Taiwan.
The gap spacer relays the string tension of the harpsichord from the bellyrail to the wrestplank, as well as supports the registers. It is prone to structural failure, and can be recognized by jacks sticking for one note and often frozen registers as well.
This video shows the replacement procedure. Jacks are seen to stick for one note. All the jacks are removed from their registers and the tension reduced. The registers are extracted from the spine window to reveal the bent gap spacer. The gap is spread with clamps and the gap spacer disintegrated along with its original support block. The support block is replaced, and the new, thicker gap spacer fitted. The clamps are removed. The registers are planed narrow for freedom of operation, the action reinstalled, and the harpsichord returned to pitch.
Three-choir Flemish Harpsichord by D. Jacques Way, Stonington 1991 Private ownership, Kaohsiung, Taiwan.