The start pin is a Klippermate product and does not come with the Gamma machine.
I would use a starting clamp if you have one. Run in the first two center mains and clamp 1RM with the starting clamp outside the frame and pull tension on 1LM. Then clamp the two center mains as close to the tension head as possible inside the frame. Then tension 2LM and move the flying clamp to 1&2LM as close to the tension head as possible inside the frame. Then tension 3LM and clamp 2&3LM inside the frame with the flying clamp as close to the tension head as possible.
Then tension 1RM, removenthe starting clamp, and use the other flying clamp to clamp the first 6 mains on the right side of the racket.
I would like to apologize to anyone I have not offended. Please be patient I will get to you shortly.