^ how to interpret that:
everything is in millimetres. so take the running length, which is the number 1525 (152.5 cm), divided by 2, which is 76.25 cm, then subtract 71.5cm (the distance to the normal mounting point) from that. you end up with 4.75 cm. I am pretty certain that's where the center is from the mounting point, but I'm not entirely sure. you should measure it to be sure.