To me it was very ridiculous. Such Russian represent to England? Korobeinik is a seller. For example, pies, or tapes. And these Korobeiniki - from a word "box". It is not absolutely correct. They - a part of game. Funny. By the way, a song which sounds in film:

"Eeh, the full box of fabrics -
there is both silk and brocade.
Buy, favourite! The box strongly presses on my shoulder.
Regret me, favourite! The box strongly presses on my shoulder!
Come the maiden to a rye high.
There up to nights I shall wait.
As soon as I shall notice you
- the black-eyed girl
then all goods to you I shall show.
The prices I paid for the goods high.
But now about it I do not regret.
Also it is ready to give
all goods to you without money.
The lovely girl, sit down to me more close.
I shall kiss you on scarlet sponges.
Katya carefully bargains,
all is afraid, that it will deceive.
The guy kisses the maiden,
asks, that kissed even more strong.
The guy kisses the maiden,
asks, that kissed it is even more.
Only night knows,
that the guy kisses the girl.
Only the high rye knows secret,
that the guy kisses the girl".

You understand my English?