1. Czech (I meant Polish! ) and Finnish Mosin Nagants have the highest quality in my experience.
2. I prefer Pre-1930's receivers because I think the markings are far more interesting and the hex design is nice.
3. Izhevsk and Tula only did very minor things differently than the other (if anything). All parts are interchangeable between the two.
4. If you have a 200 dollar budget you can buy a great quality 91/30 if you shop right.
The 31 Izhevsk sounds like a good deal for an average/good 91/30.