Longines cal. 6651 help needed

Good afternoon OF,

I recently purchased a 1975 Longines Admiral with a caliber 6651 inside it. Watch is working great but the only concern I have is that the rotor is loose and flickers a bit, making some noise when turning the watch upside down. Do you guys know if I could purchase the screw that holds it into the movement alone? Do I have to purchase a new whole rotor? Is there any "generic" screws that may fit the gap?

Thank you so much for your help, OF!

Best,
Javi.

Yes. But as it is one screw only, I thought a watchmaker wasnt needed. Thank you for your insight!