After many decades piano strings loose their tone, become rusty and are prone to breaking. At this point on a much loved instrument it is often worth renewing the strings and tuning pins.
Piano re-wiring / re stringing involves taking off the old strings in a controlled and systematic way, by measuring the thicknesses of the strings. In the example above, as the piano bass strings had been previously changed, I carefully un-hooked them and kept them for re attachment. Where bass strings are replaced, a rubbing is taken (like a brass rubbing, along with measurements) and new strings made up.
When re stringing commences, from the top downwards, each string is made up from steel piano wire and a new larger piano tuning pin is driven into the pin block. As the bass strings are strung over the treble strings, those are left till the end.
The result will breath new life into a piano, giving a brighter sound with more sustain to the notes, especially if the hammers are also changed or re-faced.