I have been down this road more than once. Depending on what your gun needs, my first question is "Do you have deep pockets"? What/how far do you want to go? Does the wood need refinishing and checkering recut? Any damage repair that needs to be done to the wood? The barrels need refinishing? Any dents? Is it tight and on face? Most important, how are the bores and what is the barrel wall thickness at various intervals. Without safe barrels, you have nothing as far as being able to shoot it goes. Bottom line, it ain't cheap and be prepared because you always find more wrong once into it.
Also realize that, depending on the amount of work your gun needs, you will likely have far more into it then you would ever sell it for if that matters.
This isn't meant to scare you off as I love seeing these old guns brought back to life. Just making you aware that such a task isn't for the "faint of heart".