Dear Hans,
This is very sad indeed, and it can definitely not be blamed to a lack of effort and productivity from your side the last so many decades.
I will write to the administrators you mention.
But they too are only reflecting the current Zeitgeist.
How different was the era of Speijer who could "surf" on a widespread wave of interest (in the world and in the Netherlands) in all things India and theosophical.
Hence the title of that other book of Speijer's, mainly on Samkhya and other Indian philosophies:
De Indische theosophie en hare beteekenis voor ons (1910; German translation in 1914: Die indische Theosophie aus den Quellen dargestellt).
Jan