I didn't restore an original diner I created my own from a Lionel 610 Passenger car.
To make the steps I used Precision Board ( a very dense foam board used by sign makers, you might be able to get scraps of it from a sign maker ) After it is painted it looks original.
For the bushes, I bought from Home Depot, a section of stuff ??? you put in gutters to keep the leaves out, you can cut and shape it to fit your diner. Spray paint it green, it looks pretty close to original.
For the windows go to an art store and get frosted acetate, cut to size, use small pieces of double sided tape to hold in place. I also added an another bulb in the car to even out the lighting.
I added a sign made from a brass plate and gold lettering.
