The original covers to the partbooks were lost when the volumes were rebound in 1950.
 However, Rimbault, who printed some of the works in his A Collection of Anthems for Voices and Instruments by Composers of the Madrigalian Era, included the following note observing the now-lost bindings in that volume's preface:
This valuable set of ancient Part-books consists of six small oblong volumes in the original binding, and with the Arms and Badge of Edward the Sixth stamped on the sides … The writing commences in the reign of Edward the Sixth, and ends in that of Charles the First, the last composition entered being an Ode composed by Orlando Gibbons for the marriage of that king with the princess Henrietta Maria.

Even without seeing the covers Ashbee noted several obvious errors in Rimbault's account.
Rimbault said the final work is an ode composed by Gibbons, but Ashbee noted it is a fantasia.
  Ashbee notes that the coat-of-arms could not have been that of Edward VI, although it suggests one from Gloucester, as well as ownership subsequent to that of Merro.

Although Monson suggested the dates of 1615-1630, Fallows felt the earliest part of the span is the more correct.
 Based on his study of the paste-down flyleaves, he felt that the collection was bound no later than 1620 in Oxford.
Ashbee suggests dates of 1615-1625 and agrees that the earliest dates are more likely.

The physical layout of music resembles that manuscripts Christ Church MSS 984-8 (The Dow Partbooks) and British Museum Add.
22597.
This might have been a conscious decision on Merro's part to acknowledge the music's historic nature by maintaining the appearance of an archaic manuscript.
In the cantus partbook (Drexel 4180), this archaic style can be seen on folios 1-16v, 18v-38v, 40-43, 54v-57 and 64v-68.
 To Monson this represents the oldest layer of the partbooks.
The original covers to the partbooks were lost when the volumes were rebound in 1950.  However, Rimbault, who printed some of the works in his A Collection of Anthems for Voices and Instruments by Composers of the Madrigalian Era, included the following note observing the now-lost bindings in that volume's preface:
This valuable set of ancient Part-books consists of six small oblong volumes in the original binding, and with the Arms and Badge of Edward the Sixth stamped on the sides … The writing commences in the reign of Edward the Sixth, and ends in that of Charles the First, the last composition entered being an Ode composed by Orlando Gibbons for the marriage of that king with the princess Henrietta Maria.
Even without seeing the covers Ashbee noted several obvious errors in Rimbault's account. Rimbault said the final work is an ode composed by Gibbons, but Ashbee noted it is a fantasia.   Ashbee notes that the coat-of-arms could not have been that of Edward VI, although it suggests one from Gloucester, as well as ownership subsequent to that of Merro.
Although Monson suggested the dates of 1615-1630, Fallows felt the earliest part of the span is the more correct.  Based on his study of the paste-down flyleaves, he felt that the collection was bound no later than 1620 in Oxford. Ashbee suggests dates of 1615-1625 and agrees that the earliest dates are more likely.
The physical layout of music resembles that manuscripts Christ Church MSS 984-8 (The Dow Partbooks) and British Museum Add. 22597. This might have been a conscious decision on Merro's part to acknowledge the music's historic nature by maintaining the appearance of an archaic manuscript. In the cantus partbook (Drexel 4180), this archaic style can be seen on folios 1-16v, 18v-38v, 40-43, 54v-57 and 64v-68.  To Monson this represents the oldest layer of the partbooks.
Drexel 4180–4185