So the bad thing with most of the good mosin books, they are they are out of print and were limited runs to begin with. Aka they are expensive and hard to find, and many of them are not in english. 😅
M91/30 rifles and M38/M44 carbines in 1941-1945, accessories and devices (Model 1891/1930 rifle) - Alexander Yuschenko
This is the main one from Alexander. The English physical printing are near impossible to find, Russian copies a bit easier. An ebook version was available on amazon and came with the sites patron subscription. However, due to the Russia/Ukriane war Alexander has not been updateing the site and the book was pulled from the Amazon store front.
Between Alexander's book and Chumak's "The History of the Three-Line Rifle Model 1891" which is only in Russian, you get about the best and most document backed history of the Russian mosin rifle. Chumak also has a great many other associated books like one dealing with referbishment and associated marks and the 7.62x54r cartriges history, of course all in Russian.
If you want Finnish info check out "Finnish Mosin - Nagant, Three Line Rifle to Ukko Pekka"- Matt DiRisio. It is good, and a fairly recent release. Best yet, still in print from Wet Dog Publishing.
Also, if you have not found it on youtube, "History of WWI Primer 074: Russian Mosin-Nagant 1891 Documentary" - C&Rsenal dose about as indepth view as you can smash in to two hours for the Mosin history Berdan to the end of WW1 M1891. Then in the next couple days they should be releaseing the M1891/30 episode.