The information you posted from the Rev. War Soldiers/Sailors lists is basically what I have. In my own research, I have nothing else at this time that has been transcribed, although I do have literally several thousand pages to get done, at some point. Right now, my hands are overful with Civil War and Regular Army research. But the following may give you a couple of other leads.

Note: These are from my own compilings, and have no surname listed. As you undoubtedly know, Cuffee in all its forms is a common slave name. But it's worth checking, since the time frame and location are right:

Cuff, 67y male, Buried in Burlington, Ma. April 1813. Death record, Negro servant of Madam Abigail Jones. Burlington Vital Records

Cuffee no age, Free Negro, intent reads Custee to Zipporah, free Negro. Boston Marriage records 2-26-1733

state record reads: Cuffee to Jephorah, by Reverend John Webb

Cuffee no age, A Negro of Dr. Gardiner to Moll, a Negro Woman of Richard Watts, Esq. Chelsea. Boston marriage records 9-17-1761.

Cuffee Private, Revolutionary War, Negro. Roll # 61, Revolutionary Service records.

Cuffee no age. Servant to Mr. Levi Jennings to Rose, servant to Eldeth Binny, by Reverend Samuel Stillman. Boston marriage records. 7-9-1773

Best of luck

Sharon