Publication: The code was publicly released to mod.sources on June 23, 1986 (cited / original usenet post)
I also found a book about CVS prior to the Priority Date (using http://amazon.com):
Another good ressource to look for Prior Art are Universities:
University Bonn, SS 99 “Softwaretechnologie”, contains in homework 3 extra homework on CVS, especially for the commands checkout, update und commit
So I see it as defenitely proofed, that CVS was published prior the Priority Date of the Invention.
And if you find sth. like Der „MetaCodeGenerator“ arbeitet mit allen markt-üblichen CM-Systemen wie Visual SourceSafe, ClearCase, CVS, ….
, where the patentee itself says that CVS is one of the major source control systems and which was published prior to the Priority Date, then it even starts to make fun searching for Prior Art
(link to prospect