Field Options Flicker Removal worked! Smoothed out the lines quite nicely, great suggestion Jon.
Shane, I assumed the lines were baked in, as I’m pretty sure the footage was captured properly but exported improperly (nobody paid attention to how footage was archived back in the day), but applying Flicker Removal did the trick, so I’m happy. I’m definitely using this for all the other archival footage I’ll be needing to rework in the future!
Thank you!