Let's see...
Russian Assault:
EIBRA\Gostek-gfx and EIBRA\Gostek-gfx\Team2
There's no interface except small elements like star, arrow and noflag. Main difference in gosteks are some altered colors, little shapes and headgears.
EIB3:
Copy Europe in the Battle 3\Custom-interfaces to Soldat\Custom-interfaces.
For modified default interface copy Europe in the Battle 3\Interface-gfx except Guns subfolder and paste to Soldat\
For different teams, open Europe in the Battle 3\Gosteks-gfx folder and choose set of gosteks (American, British, Polish, Russian). Inside each of set is Gosteks-gfx subfolder (in ex. Europe in the Battle 3\Gostek-gfx\American\Gostek-gfx) Now copy that gostek-gfx folder and paste into Mods\Europe in the Battle 3\