Yes it was the "Paul Simon Songbook" I was thinking of from 1965. The track listing from that album is interesting, the only track I think that Simon & Garfunkel didn't do is track 9 "Side of a Hill" which Paul Simon wrote under a pseudonym as Paul Kane.
1. I am a Rock
2. Leaves That Are Green
3. A Church Is Burning
4. April Come She Will
5. The Sound of Silence
6. A Most Peculiar Man
7. He Was My Brother (Paul Kane)
8. Kathy's Song
9. The Side of a Hill (Paul Kane)
10. A Simple Desultory Philippic
11. Flowers Never Bend with the Rainfall
12. Patterns
In 2004 the CD Reissue of that album had alternative versions of "I am a Rock" & "A Church Is Burning".
While "A Church Is Burning" wasn't featured on any Simon & Garfunkel studio albums (unless it's a rare track), Simon & Garfunkel performed it "Live From New York City, 1967". I'm unsure if Simon & Garfunkel did "The Side of a Hill" if they did, then it would have to be another Rarity.
But as I said earlier these tracks while S&G did many of them, they were alternative versions Paul Simon did from the UK, though as you can see it includes a bit from Wednesday Morning 3.A.M., Sounds of Silence & even a bit of Parsley, Sage, Rosemary & Thyme.
Ok, last minute info I got here about "The Side of a Hill" is it became incorporated into the S&G track that we know as "Scarborough Fair/Canticle".