Capacitor on firewall?

[68isgreat]

Hello, newbie here. I've got a crusy 68 short narrow stepside with the original 250 six, and I'm going to try to get it running. The tags say '98, so it appears it has been sitting since then. There's a small capacitor coming out of the wire loom and screwed into the firewall above the wire junction block. What is that for? Is it just a radio noise capacitor? It does have the original AM radio. Not sure if I should replace it or not. It's old and rusty.

Also, separate question. The engine turns over but isn't getting spark, so I'm replacing pretty much everything, and staying with points and coil for now, until I get it usable. While replacing the coil, I see that the yellow wire from the coil was spliced to the thick white fabric shielded resistor wire from the firewall, and then another 20ga yellow wire goes from there down to the starter. Doesn't that negate the point of the large resistor wire? Should I extend the large resistor wire down to the starter by itself, and then run a separate yellow wire back to the coil? Or am I supposed to run the large resistor wire straight to the coil, and a separate yellow wire from coil to starter?

Thanks! Pic below of the crusty old engine in question.