Today's tensions in the part of the world where most of the surplus 7.62x54R comes from has noting to do with what is on the shelf today, although it could affect what's going to be available in a few months, or possibly slightly sooner.
The simple fact is, since the change from full size infantry rounds (.30-06, 8mm Mauser, .303 Brit, and even 7.62x54R) to intermediate size rounds in the rifles carried by the troops, supplies of the bigger, older designed rounds are reduced.
Several of the full size rounds still soldier on, as machine gun ammo, and likely will for a long time yet, but the huge supplies of non belted type stuff left over from the decades of war have been put on the market and are essentially now about gone.
The calibers of the former Communist nations were the last of them, and only because until the fall of Communism (soviet, in particular) neither the guns, nor the ammo was available to the US market.