I think there should be the Zinc Casing variants of both Gearboxes + the Configurable Gearbox, as well as the Press, Mixer, Depot, Encased Chain Drive, Adjustable Chain Gearshift, Chain Conveyor, Gearshift, Clutch, Automatic Clutch, Deployer, Portable Storage Interface, Encased Fan, Mechanical Harvester, Mechanical Saw, Mechanical Drill, Mechanical Plough and Mechanical Roller.
I think the priority should be the Configurable Gearbox.
I think there should be the Zinc Casing variants of both Gearboxes + the Configurable Gearbox, as well as the Press, Mixer, Depot, Encased Chain Drive, Adjustable Chain Gearshift, Chain Conveyor, Gearshift, Clutch, Automatic Clutch, Deployer, Portable Storage Interface, Encased Fan, Mechanical Harvester, Mechanical Saw, Mechanical Drill, Mechanical Plough and Mechanical Roller.
I think the priority should be the Configurable Gearbox.