this is a picture of carsons in chicago, a bit ornate but gives you an idea for street backdrop.

You could combine the forms in these two pics to create the street scene.  the corner entrance could be 3 d and project from the back drop.  and you could place the  newsstand on the left side and forward and get some street depth..a lamppost or two and you got a nice street scene.

this is just a corner but would make a neat centerpiece on your street scene   turn the windows to doors into the store and expand it a bit.

another street front that would make a nice backdrop idea.

this is the interior of marshall field in chicago about the time you are doing the show.    This gives that perspective idea i mentioned. and you could have more counters on the left side or a big xmas tree and maybe the last few steps of a grand staircase coming in from the left out of the wings.  and elevator doors on the back wall left.

this is the tiffany light court at marshall field.  You could do a forced perspective like this to get some great heigh to your interior set.  Depends on how high your proscenium is on the stage. the ceiling is tiffany glass dome. At christmas there is a huge tree in here.

another wall counter idea to show vast space.  what you see in the arches could be faux painted view. or blownup photo or mirrored surface of some kind.