Here is an interesting article by Aaron Ember, professor of Egytptology at Johns Hopkins University called 'Pronunciation of Hebrew among the Russian Jews,' from 1903 (The American Journal of Semitic Languages and Literatures, Vol. 19, No. 4. (Jul., 1903), pp. 233-234). It doesn't say if he travelled in Russia, but it seems like he must have.
There is really nothing in it that most readers will not already know, but its fun to read. It notes what is familiar as the classic 'Litvishe havara,' for example, reading a holem as ei and pronouncing both shin and sin as samekh.
It contains errors, for example, it approves of
Gesenius's Grammar is many things, but on this point it is mistaken, but in 1903 it was still an important authority on Hebrew.
You can download it all here.