The rejected "If You Gotta Go, Go Now" single eventually saw the life of day as a 1967 release in the Benelux countries only, backed with "To Ramona" from Another Side of Bob Dylan. A planned EP release in the UK was apparently cancelled (see Hermann Anschlag's self-published 1982 book on Dylan's singles and EPs, Bob Dylan: Small Talk).

Small Talk, p.63

That last paragraph, translated, reads:

 This EP can only exist in very limited numbers, as it is supposed to have been withdrawn by Dylan shortly after its release.

Given that no copies have surfaced in the following half-century, I think it's safe to assume that it never even reached the pressing stage.