The biggest part for flying into Moscow in an aircraft that doesn't have a metric swap for the altimeter is.... metrics.
You reach a point where you leave RVSM airspace flying east and then enter the nether-regions of Eurocontrol where you transition to "meters". So you'll be cruising along at FL330 and then when you transition, they'll say "climb an maintain FL 110 meters standard" or something like that. Then they'll descend you through the flight levels using meters, and to add insult to injury, when you're on the arrival and beneath the transition level, they'll say "descend and maintain 800 meters, altimeter 1019"... Then you've got to request QNH because they've probably just given you QFE which will leave you in a world of hurt if you don't convert it.
You'll be converting every altitude from cruise, to intermediate altitudes, all the way down to the approach.
And there's not a lot of reliable radar coverage so tell your dad to be ready to give position reports.