The 77 clock and tacho is available repro in Quartz form, the 79+ type is not. As Brian said, there's kits for the clocks if needed, I don't think the clocks were available new outside of the complete tacho. The components of the clocks are not interchangeable, new or used. They stay with the tacho type, round rear is early, flat sided oval rear is 79+, even if clock doesn't say Quartz. Lettering appeared later to confirm