Alternator started sparking

I have a 1973 Dodge Dart Sport with a MSD 6a digital ignition, blaster coil, MSD distributor and unknown after market wiring harness. I recently had issues getting power to my ignition and it also wouldn’t crank. After double checking wiring and cleaning the posts on the battery, it started working again. Fast forward a month of it sitting over the holidays and it won’t crank again. I’m guessing it’s the NSS, but I’m not certain because my floor jack decided to stop working yesterday, so I haven’t been able to check. I can start my car by jumping it at the starter relay though. After letting it idle for a couple minutes yesterday, I started to advance the timing a bit and my alternator starting sparking inside of the cage. I don’t know if the two are related. The wiring on the alternator seems fine. No burnt or melted wires. Any insight would be appreciated. Thank you in advance.