The game has been updated with a new parts inventory system. Hold ‘Q’ when in game to bring up the inventory screen. You can then click on parts in the inventory to add them into the world, ready to be used for construction. Any part in the world that isn’t part of a construction can be added to your inventory by running / walking over it.
Right now each part in the inventory screen just has a text descriptor, hopefully I’ll soon be adding a preview image for each part so you can more easily tell what it is, watch this space!