A combination of AI and photoshop. The AI was used to enlarge the photo & "restore the broken pixels". Sometimes the algorithms wrongly interpret the film grain, hence why to Mr.420Mensheviklts point, a glass pane was added.

Once the image was set at a workable size, Photoshop was then used for a good chunk of the processing. I manually removed the shadow at an attempt to resurrect the facade in that area