Russian Diplomatic Ciphers in the 1860s

In 2016, I posted a specimen of a Russian diplomatic telegram in cipher at the time of the Alaska Purchase (1867), and called for information on the kind of cipher employed. Now, I was taught by Mikhail that Russian diplomatic ciphers in the 1860s are described in a book in Russian, which he kindly explained to me. It is a polyalphabetic cipher based on mixed alphabets, with a daily key consisting of 8 strips with 20 letters on each (i.e., the key is 160 letters long). This must have been among the best in the 1860s.
I updated the article: "Russian Diplomatic Cipher at the time of the Alaska Purchase (1867)". Now that the system is known, there remains a task of aligning the ciphertext and the plaintext and reconstructing the key. Any further information will be most welcome.