my guess is wires; cap and rotor should be done too.

I replaced wires with a set of the stock braided wires on my SC with no issues.

That thin shaft w/ circular handle is a plug. You remove it to expose the adjustment screw which is down a couple inches. You need a 3mm allen wrench about 5" long to turn it. As seen from the top, clockwise is richer. BE CAREFUL. Without a baseline you have no idea what your CO is. Unless you have a lot of experience w/ the CIS system, it's easy to overdo the adjustment. One complete rev is somewhere between 8 and 12%. John Walker has advised a CO of about 3.5% for best running, unless you have to meet some emission standard. Too lean and you could burn a piston.

After you do your new part swap in, it would be a good idea to have someone w/ a meter set your CO for you. Shops don't charge much for this, and you know your setting will be safe.