One other consideration I didn't see mentioned with these, is the bore, many can have rough bores or worse, sewer pipe bores. The gas system might be another area worthy of inspection, it can suffer the same corrosive effects as the bore saw. I found one local several years ago, nice wood, it was pretty, all was go till I looked in the barrel
I think it might have still had rifling, in spots.
My worst Mosin bore would have been sniper grade compared to what I saw in that tube. Usually parts are hard to come by, which is not a big deal, you can find them with some searching, and a replacement mag usually is a pretty penny.
Surplus is getting hard to find, but at times, 7.62x45 is still loaded commercially, Buffalo Arms does load it in reloadable brass, pricey yup, but you get the brass with it..
http://www.buffaloarms.com/762x45_Ammunition_it-158118.aspx