CFS was my wife's, uncle's Grandfather. He put aside the ebony and ivory for the keys in 1934 when his grandson was born. Bear with me as I'm not piano educated. It is an upright, rehearsal grand. It has his name "stamped" on the aluminum plate inside. He made this just for his grandson in 1969, there is a handwritten date inside.

I'm sorry I can't answer your question as to value, but this is of interest to me because I have a Charles Frederick Stein baby grand piano that's now on loan to my nieces. It was made about 1926 and restored in 1973 when my parents bought it for me at Whittle's Music Company in Dallas, Texas. I hope to get it back someday, at which time it'll need some more work, I'm sure. ;-D

I occasionally do a search on "Charles Frederick Stein" and from what I can tell, he was a Chicago builder whose company closed in the 1940s, but I read somewhere that he hand built his last piano for his granddaughter when he was in his 80s! Might this be that piano? That might make it of historical interest to somebody beyond its actual worth. You'll need to get a professional assessment as to its condition from a piano tech, anyway.

I'm not sure what you mean by "upright rehearsal grand." Usually a piano is either an upright OR a grand, but not both, unless it's the brand name "Grand" which creates a lot of confusion on Craigslist,LOL.

What does your wife remember of the man himself? He's described in Pierce Piano Atlas as "The Dean of Piano Men." I'd love to see a picture of your piano if you could post it.