John, on page vi of VRs of Rehoboth, Volume 1, it states this is an "index" and does give the "book" number and "line" number of the appropriate entry.
As you stated, Ame Campe, daughter of Nicolas Campe Jr and Ame, is annotated in book 2, line number 229. These VR Books are normally maintained by the City Clerks office. I don't know if other arraingments have been made for those records or not, but your first check should be with the City Clerk. If the book is available and accessible, I would use a digital camera to take a picture of the appropriate page, the title page if any and the cover of the book. You can also ask for a "Certified Copy" of the birth information from the clerk.
From their web site;
"If you are interested in conducting a genealogy study in Rehoboth, we do have permanent town records dating back to 1633 at town hall.You also have several research options available."
More information is available on their web site, here;