Besides the rust, there is another problem with this picture. The wire coiled around each tuning pin is flush against the plate.

This happens after several decades of tuning and settling, and is largely unavoidable. Once the coil is touching the plate, tightening the tuning pins is difficult and the piano’s tuning stability can suffer. Eventually the tuning pins have to be replaced with a slightly larger size, at which point it usually is most sensible to simply re-string the entire instrument because of the labor involved.

Fortunately, this piano was about to get re-strung anyway!

tuning-pin-coils