A small update, I got an Astromech Club official restraining bolt from Geir, who is currently building an R2 Unit in Oslo. The restraining bolt is in machined aluminium, with a strong magnet glued to its underside. I plan on putting a piece of metal/magnet under the torso as well, such that the restraining bolt can be put on/taken off while being in costume. That’s gonna be awesome!
The restraining bolt needs a bit of weathering, and detailing with Humbrol enamel black paint, and probably some cloth glued to its underside such that it doesn’t scratch off the VM’d-gold surface.