It's a 2003 so with only 700 miles on it so it's been sitting a while. The starter bendix might have some corrosion on it or even benefit from a few drops of oil even though Piaggio discourages oiling it. I would still begin with charging the battery fully to see if that's the problem. If that doesn't help, here is a video as noted above. By the way, I don't recommend the variator part of the video, they didn't remove and clean the fixed plate and the Motorsport lx150 video shows that part better & easier.
Bill