Dear Donia,
Q. Dear Donia,
A. Dear Lorraine,
What a wonderful document and an excellent question. It is not a good idea to try to restore signatures or documents by inking over them again. You lose the historic integrity and they never come out looking right. The best thing to do is to get the document digitized and digitally enhance the lost writing. Most likely, the ink used in the document was iron gall-based which fluoresces a deep velvet black under UV light so be sure to find a digital photographer who has this capability. I have no doubt there is someone in the DFW area that can do this for you. A good starting point might be contacting the folks at the University of North Texas' Special Collections in the library. They would know the photographers in the area that would be able to help. Good luck!