Talk to Stanley on the far left of the map, select "Maybe you've got something interesting in that trolley", "Inflatable bed with a pump" and "Maybe he can tell me if he's looking for something in particular".
Now go talk to granny and select "She's got big eyes", "What a large head", "I can't see anything bigger than her head" and "I'm going to ask about grandad".
Go talk to grandpa (Nika's house, second floor, first door), select "I'm going to tell him what Grandma thinks of him".
Now that he's gone, click the light switch and examine the code, take out the picture of young grandma and interact with the box to open it, get the magazines from inside.
Give the magazines to Stanley and he'll give you the air pump, combine it with the air compressor on your list.