The screws are designed so cheap that this is an absolute vulnerability on Rig.
Regardless Three new M6 Allen screws in and ready.
If you want to use the rig as Cage, a self-made Tarver by a handle on the other hand is recommended because the ganbze otherwise unstable (By writing a 7d and 24-70L it)
Good solved the many threads are also in the handles. so you can if you want to screw still counterweight in the shoulder use.