Matryoshka Doll 1 - This will be found on a barrel next to the trip mine wall buy in the stamin-up part of the map.
Matryoshka Doll 2 - This is found on the desk near where the gobblegum machine is, on the first floor of the building that has the power switch.
Matryoshka Doll 3 - This is on top of one of the electrical boxes right next to speed cola
Matryoshka Doll 4 - This is on the shelf directly to the left of Widow's Wine.