Hello, I have just bought an old Rayco BR-3 stringing machine. I am very much interested in learning how to string racquets. The problem is that I cannot for the life of me find any information on the BR-3. How do you clamp down the racquet? Would you happen to have any photo that could clue me in? I saw one of your comments on a BR-3 post, thus my inquiry. Cordially, Vu