No probs with Russia. There are now so many folks out there to assist from the Int'l Handlers like Jeppesen (use Jepp UK), UV (use UV @ STN), Air Routing (use Terry Yeomans @ LTN office), Base Ops (use BASEOPs Europe near LGW) etc., to the direct contacts with the following all in MOW:
Rusaero
www.rusaero.aero as for Igor Mudrik or Misha Titov
Streamline Ops
www.streamline-ops.com
FERAS
www.feras-cis.com
Most important thing is to get your credit lines sorted.
Have a fun trip, I've been sending folks there since early 80's with very, very few snags.