I have strayed to Web pages of Jozef Pilsudski Institute
of America in New York with a listing of its archives.
In the listing of its archives (not in English yet):
http://dione.ids.pl/~ijp/pol/aog2.html
under LANGENFELD Witold Karol (ur. 1896), and T. 9 [vol. 9]
of the materials presented to the Institute by Ludwik E. Michael
there are some manuals, which include (translating the titles):
_Cryptography_, _Wilfrid Cypher_, _Beginnings of cryptography_,
_Memory cypher_ - all in typescript, without author or date.
_Wilfrid cypher_ is obviously what alarmed me. Is a cypher
by that name known? Or was there a tradition of a cypher
invented by Wojnicz in Poland and knowned by his conspiracy
pseudonym?