This book details the history of the Russian invented rifle - although it does have assemble diagrams of the weapon it is not a comprehensive 'fix it' book.
However, it does have a great history of the rifle including the use by USA troops. It's little known, that the US and Allied troops fought in Northern Russia using American made Mosins. The Mosin–Nagant 91/30 was the standard issue weapon of Soviet troops in WW2. Virtually every country that received military aid from the Soviet Union, China, and Eastern Europe during the Cold War used Mosin–Nagants at various times.
Mosin–Nagant rifles are still found on modern battlefields around the world. Russia has issued the rifle to conscripts from both occupied regions of the Donbas, and to conscripted Russian civilians as part of Vladimir Putin's wider general mobilisation during the 2022 Russian invasion of Ukraine.
Would be a treasured book for anyone owning a Mosin-Nagant M1891 or variant.