C-3PO Chest Piston
Another part I designed based on pictures and parts I could find. An original design of my own, but obviously meant to look like the chest pistons of C-3PO.
There is a hole in the bottom that will accept a piece of 12 gauge wire to use for mounting to the upper chest of C-3PO.
I recommend printing this laying down. The print might be a little rough on the bottom edge, but I think with some tweaking of the print settings, this can be minimized. Even with issues, the rough spot can be oriented against the rest of the chest, and mostly hidden.