From the Undead Mechanic quest, introduced during the Reign of Terror event.
Missing Mechanisms
Alloy Device Alloy Apparatus Alloy Instrument Alloy Tool Alloy Contraption Alloy Implement Alloy Utensil Alloy Mechanism Alloy Cogwheel Alloy Contrivance
Alloy Sprocket Alloy Cylinder Alloy Dynamo Alloy Piston Alloy Fan Alloy Pinion Alloy Engine Alloy Motor Alloy Generator Alloy Turbine