Iverson 1876 Baby Grand Piano

I have an antique Iverson Baby Grand Piano from Boston.  I think the year is 1876.  It is VERY heavy.  Just the legs (which screw off) are heavy.  It is a dark wood.  Measurements are back to front 38", side to side 76",tall 37".  18 keys have small chips.  One key is missing 1/2 of the ivory.  Could you please tell me it's worth?  We called a piano tuner several years ago.  When he came over he did not bring tools because he thought he would not be able to tune it because he said due to the age the wires would be brittle and break.  He had to go back to get his tools to tune it. He said it was in good shape but if I wanted my kids to seriously be pianists this was not the piano to teach them on.  Could you please tell me it's worth?  I forgot, the 3 fold top can lay flat and totaly cover the keys etc, or you can fold it open to play piano, or fold it open even more to expose the wires and play the keys.  Could you please estimate it's worth?  Thank you. It is a VERY beautiful piece of furniture.