When tuning and regulating no longer work, it means your piano needs to be restored. Your piano can be completey refitted with brand new strings, action parts - including hammers, wippens, dampers, and all the parts that support them.
There is a wide variety of optins available, depending upon your taste and budget.
H. HANSEN Upright Piano (German, 1895) Before and After
WEBER Baby Grand Piano
STEINWAY 1920 Before and After