A printer includes a pair of opposed printhead assemblies for double-sided printing. Each printhead assembly includes first and second print modules having respective first and second elongate print heads. A single printhead circuit board controls both of the print modules and is coupled to them by means of a flexible PCB. Contact pads on the flexible PCB abut terminals formed on moldings of each of the print modules. In order to reduce manufacturing costs the moldings are mirror images of each other. Ink reservoirs are formed in the moldings with ink ports located at either end. Plugs are inserted into, and seal, the outermost ink ports.