My piano has 36 white keys & 52 black keys. It is a baby grand with matching bench. It doesn't seem to hold a tune-up, and 1 key doesn't work. I can't find a serial number. It does have the name Sphaff Co. est. 1868. The Name, "Harriett" is written underneith on a cross member. There's also a "2" carved underneith. Can you tell me anything about it? And, is it worth restoring? I bought it 25 years ago from a private home. My children played it for many years. Thank you. [email protected]