I have translated now seven capitulations articles starting with the capitulation of town and citadel of Erfurth and as noted above Lubeck. Most of these are already posted. Perhaps the most poignant of these is Hohenlohe's letter to the King of Prussia trying explain why he capitulated his forces.
These letters were published in French probably from the originals or copies of the originals, as the French goes on to list who signed the document and who authorized the signing etc. The capitulation of the Saxon grenadiers, at one point says "there follows the signatures of all the officers of the regiment."
I don't know how the editor/publisher got these documents. At first when I was translating mostly diplomatic documents I had assumed the editor was a close friend of Talleyrand who was having these published to assure his own political ends. Why or how all these letters, and documents got to this source I do not know. Nor has anyone found a similar book (or even the second volume) to my knowledge.
I obtained it from a bookseller in Canada bought it at an estate sale many years ago, and did not remember if there was a second volume. He could only recollect that the gentleman was an avid historian who donated most of his vast library to the province of Alberta.