“I’m going to change the plugs and wires (they need it, anyway) and I’ve ordered a new ignition coil, which I’ll also switch out.”
Since, as Tester noted, that code indicates a misfire in one of the cylinders, I think that the likely cause is that one of those admittedly overaged spark plugs is the source of the misfire. If new plugs and wires don’t cure the situation, then perhaps the coil will be the answer, but I think that it is premature to “throw” a coil at the situation until you know whether it is needed.