An engine servicing facility for the JGL

[Sumpter250]

Now I need to make some stairs and a sidewalk, and think of how to turn that black foamcore into a macadam parking lot!

Some white stripes (I don't remember yellow from that era), some "patches", some filled cracks ( felt tip extra fine drawing pen ), maybe a pile of "butts" where some slob emptied his car's ash tray ( also maybe not an era specific detail ), and enough vehicles, of the right ages, to look like there's jobs there.
Looking good!