Hi archery rob, I contacted Barnett and even sent them photos of the xbow but they were no help and even denied that it was one of their bows, however the plans that came with the kit definitely had "Barnett Black Panther" and their logo. Bear in mind this was some 48 years ago. I make my own longbow strings and whilst I know that a crossbow string is a little different I am confident that I can make one. My problem is that I do not have an old string and therefore do not know how long to make the new one. I guess I'll just have to experiment.