I'm listening to Simon & Garfunkel's Parsley, Sage, Rosemary, and Thyme, and I'm pretty sure that there are two bass parts in "A Simple Desultory Philippic." There's one panned left, and other panned right with fuzz-tone. I'm not completely sure that the right-panned one is bass, but in any case it matches the bass part pretty closely.
I haven't listened to it for awhile, but apparently "Think for Yourself" from the Beatles' Rubber Soul has two bass parts too - one regular and one with fuzz tone. And since "A Simple Desultory Philippic" contains a reference to the Beatles ("I’ve been Rolling Stone-d and Beatle-d ‘til I’m blind"), I think the similarity is intentional. The Bob Dylan pastiche is clearly intentional, so why not the Beatle one?