There never had been kvas from wooden barrels in Moscow in 1982 or after. Kvas was sold from metal trailer tanks like this one: http://mtdata.ru/u22/photo30E5/20831353979-0/original.jpg till 90s and then it was gone (I left in early 2000s though I doubt wooden barrels with a cup on a chain appeared later).
Stuffed potato is not something Russians eat, least something so popular to be sold on the street. So, again, it was not sold in 1982 or later.
Blinchiki is something that could have been possibly sold since Russians do eat them. I've never seen them sold on the street myself but I cannot possibly say it's as ridiculous as stuffed potato.
Stuffed potato is not something Russians eat, least something so popular to be sold on the street. So, again, it was not sold in 1982 or later.
Blinchiki is something that could have been possibly sold since Russians do eat them. I've never seen them sold on the street myself but I cannot possibly say it's as ridiculous as stuffed potato.