Sounds like the keyboard may need leveling. The paper and felt punchings on the balance rail will need to be added to (or removed) to make the keyboard level. You will need to get a supply of punchings of various thicknesses from a piano supply house to do this job.The action will also no doubt need regulation; probably the hammers reshaped as well (do this first).Removing the action from a spinet is a bit tricky, as you will discover. After disconnecting all the stickers from the ends of the key sticks, you will have to tie them temporarily to the action frame in order to be able to lift the action out.