I worked at the Sheep's Head from 1979 to 1981 and a half. I came away with the whole wheat bread recipe and the Mulligatawny soup recipe. As for the soup, you know it was flavored with Courvoisier...the secret ingredient, otherwise it was Campbell's!
I used to sit on an upturned bucket and watch Jo, the dessert cook, do her thing, and chat with her till the wee hours. As I recall, she did use the Joy of Cheesecake book for some of her cheesecakes, if not all...? I esp. remember the Kilimanjaro cheesecake.
I am trying to locate Diane Ochs, who was married to the owner for a time, and may have many of the recipes. You can reach me at firstname.lastname@example.org. We can chat some more!