As-Salamu ´Alaykum, The Didache is believed to have been written anytime before 250 A.D. Most Bible scholars will date it to somewhere around 75 - 125 A.D It is not an "Old Bible", rather a tract of teachings believed to have been written down by Nabi ´Isa's (´alayhi al-salam) Disciples, or their Followers. While it was not accepted in the Canon, it was counted as writings of the Apostolic Fathers, and while held in high esteem, held a secondary position. Yes, the books of Apostolic Fathers came to hold less and less weight in the Church. While I believe going back to these type of writings is of importance, and that it will give us a clearer and broader picture of early Christendom, I still believe that most Muslims will be disappointed in their findings. I say this after conducting Biblical researches for several years, including examining manuscripts with some of my aquaintences. Either way, the Didache is definitely one of the most interesting non-canonical readings, and it would definitely have potential to be included in the Canon. wa'Llahu a'lam