Many of the leaves and cuttings I encounter can be traced back to the collection of Robert Forrer, who we have encountered in several previous posts. I know that he sold individual items, as well as substantial collections, to Museums. In 1899, for example, he sold a collection of 1,200 specimens of early textiles to the V&A Museum. But I cannot recall having found information about how he dispersed his collection of manuscript leaves and cuttings.
I recently found one such piece of evidence. The leaf from the Arenberg Psalter discussed recently was offered for sale by auction in Leipzig in 1911, just a few years after Forrer published it in his 1907 catalogue:
In the same catalogue were other leaves we have looked at before, such as the one discussed here:
A decade after the Leipzig auction, another one, dispersing the collection of Rudolf Busch, was held in Mainz:
The foreword explains that
"Rudolf Busch war der erste Deutsche, der Manuscripte aus den berühmten Sammlungen Firmin-Didot, Robert Hoe, Henry Huth in seiner Sammlung vereinigt hat. Außerdem hat er eine größere Sammlung von Einzelminiaturen von R. Forrer in Straßburg erworben, die durch die beiden Bände "Unedierte Federzeichnungen, Miniaturen und Initialen des Mittelalters. Straßburg 1902 und 1907" schon seit längerer Zeit in den Kreisen der Kunsthistoriker bekannt geworden ist."This catalogue includes about sixteen ex-Forrer items, including the Flagellation and Crucifixion leaf of the Arenberg Psalter, as lot 282: