Friedrich Wilhelm Conrad Horster products was popular in sweden.
The swedish magician Jean Bartholmi, (Folke Rydberg) 1896-1975, invented some original effects that Conrad Horster produced.
He was a good magician plus he was a great craftsman, he was also an engineer. My magic mentor when I was a junior; Safiro (Gsta din, 1922-, rebro), was a close friend to Folke R.
Long time ago Gsta din worked in Holland and had some contact w. the famous Henk Vermeijden - Fred Kaps mentor.
There is a booklet published in swedish written by Conradi, F W (Horster, F W C) Title: "Den moderna trollkonstnren", 1931.
Swedens oldest magic company; Harries had lot of business with C-H.
You should make all C-H books available as ebooks.