As to "October Song" Countess Richard suggested the following found in another thread

"(E)I'll sing (A)you this (E)October song
there (B7)is no song be(E)fore it.
the words and (A)tune are none of my (E)own
for my (B7)joys and sorrows (E)bore it.
Beside the (E???)sea the brambly (E)briars
in the (B7) still of (E)evening,
birds fly (A)out behind the (E)sun,
and (B7)with them I'll be (E)leaving.

Someone suggested Dm instead of the dodgy E which sounds marginally better."

Looking at "The Incredible String Band" song book they give the following:

Beside the (E7)sea the brambly briars
(B7)in the still of (E)evening,
birds fly (A)out behind the (E)sun,
and (B7)with them I'll be (E)leaving.

OK They have it in G(D) but the thought is the same.

HOWEVER they give the song in DADF#AD tuning, in the key of G, played with the capo at the 5th fret, using the appropriate given chords (with 2 different G chords). Perhaps done like that the E7 probably sound better.