A further look at the three sources with images on Sarah (Thorndike) Low's profile, all from from "Massachusetts, Town Clerk, Vital and Town Records":
Looking back in the microfilm from image 493 (of 589) to image 476 labels the microfilm as "Essex County Town Hall Beverly Mass" and on image 478 the book binder is labeled "...Town of Beverly Vol-4";
Looking back from image 63 (of 610) to image 3 labels the microfilm as "Essex County Court House Salem Mass" and on image 6 the title page says " The Records...copied by order of the County Commissioners, by Alfred and Kimball, 1856";
Looking back from image 156 (of 610) to image 132 labels the microfilm as "Essex County Court House Salem Mass" and on image 134 the book binder is labeled "...County of Essex".
Looking back on the last source (not labebed but image 57 of 181) to image 1 shows a title page "Record...collected from the Essex County Records..."
Some of the original Ipswich books were lost in a fire. The first three sources above are from collections of the records occasionally sent to the county clerk by the town clerk and the last is from a town book of records copied from these county records (the marriage was recorded by the town clerk, the clerk sent a listing of marriages to the county clerk, the county clerk copied the records into the county books, the Town of Ipswich having lost their original books had made copies of the county records.)
Some clerks kept records of families on one page, thus the interleaving of several clerk's handwriting in one book and a continuous list in another.
The record of this marriage in the Tan Book (Vital Records of the Town of Ipswich, V2, p.290) labels this entry "CT.R." which means it was copied from the county records and not the Ipswich records or a private source.
My source for this additional information is the (late) long time City Clerk of Gloucester Fred Kyrouz; I spent many hours in his City Hall vaults examining similar books in the course of property title searches and learned a lot about municipal record keeping.)