He says in the trailer he has ''killed people, smuggled people and sold people'' and the russian mafia are known for smuggling and slavery etc.
I just thought it was interesting how they are both Russian and both where in previous GTA's and maybe there could be a connection.
And about the scars, In GTA2 it was 2013 and he was 41. By the looks of things GTAIV does not look like its in 2013 and he does not look 41. Those scars could of happened after GTA IV.