Adalbert Freiherr von Lanna (1836-1909) of Prague

On a recent visit to Sotheby's I was shown a lovely leaf from a Book of Hours, with a small miniature depicting St Margaret, and a border with a cherub and centaur:

It is painted on the verso; the recto is ruled, otherwise blank except for a pencil number '597', and a collector's ink-stamp:

The stamp had already been identified as belonging to Adalbert Freiherr von Lanna (1836-1909) of Prague. It appears on the Lugt Marques website, with a considerable biography; the Lugt database is not working today, so I provide instead a scan from the printed edition of the beginning of the entry on Lanna:

The "Lanna-Prag" sale of manuscripts, which took place in Vienna in 1911, is fairly well known:

Unfortunately it does not have many reproductions, but it does include this Flemish border in a Book of Hours of c.1500:

The same border was reproduced when the manuscript was re-sold a decade later from the collection of Rudolf Busch of Mainz (Baer, Frankfurt, 4 May 1921, lot 272):

It was later sold at Christie's, New York (21 October 1977, lot 103), bought by H.P. Kraus and broken up, this leaf making another appearance at Christie's (28 November 2001, lot 6):

Less well known than the 1911 Lanna-Prag sale in Vienna, is the fact that a number of interesting leaves were dispersed in another sale the previous year, in Stuttgart:

and so I was pleased to find that the St Margaret leaf, with its centaur border, could be identified in the 1910 catalogue: