A recent comment on the blog by commenter Jean Luc highlighted that there is a Vietnamese book that claims to be a previously unknown prelude to Spalding’s Life and Teaching of the Masters of the Far East.
Hanh Trinh Ve Phuong Dong is listed in Google Books, and can be found in libraries via Worldcat. Jean Luc reports it was translated in Vietnamese in 1975 from a 1924 Indian book titled Journey to the East. The first publication date shown online is 1987, with Spalding listed as author and Nguyên Phong as the translator into Vietnamese. According to Google Books, Nguyên Phong has translated similar books in the mystic and occult genre, including works by Lobsang Rampa, Myodo Satomi and Mika Waltari.