Thanks
NYC SUBWAYS – Actually the cement wall and tunnel entrance were copied from BMT Brighton Line. https://www.nycsubway.org/wiki/Main_Page
I cut 1x2 sticks, bent Masonite on the curve, applied Styrofoam with liquid nails and sanded. All cement is painted with linen. Added utility lines, signals, graffiti, and overgrown bushes. Added a power sub-station building on top of the entrance between modules. Below is the inverse from the photo you posted.
Looks like you are doing some nice modeling on the subway scenes.