All 3D parts

Filament Colorfabb nGEN gray
Filament Colorfabb FLEX black
Servo motor Modelcraft VSD-15E
8 x m3 nuts
2 x 16mm bolt (DIN 912 m3 x 16 12.9)
2 x 40mm bolt (DIN 912 m3  x 40 RVS)
2 x 45mm bolt (DIN 912 m3 x 45 RVS)
2 x 50mm bolt (DIN 912 m3 x 50 RVS)

10x 9,5mm screws (DIN 7983 2,2x9,5 RVS)

Building it togetter,

Added mini servo

Place gears, you have to cut the original servo star plastic to fit into the gear.

Take some tape to hold the nuts on place!

All parts togetter to bring into the bottom part.

Parts placed into bottom holder. (check servo wire)

Add flexible vilt at the grip left and right

drill holes and screw them onto the grip.

Grip with flex vilt

Grip added to body

Both grips assembled on body.

Some pics of the result, ready to use.