Vintage work crew photos

[Toolmaker51]

Those "slit" beams look like 6" nails to me, not slits. You can see them better if you blow up the picture and look at some of the items that are hanging on them.

https://diqn32j8nouaz.cloudfront.net...w_fullsize.jpg

Yup, 'slits' are nail shadows. 1930's would need decent lighting in foreground to overcome backlit exposure of windows. There is a deep field of view denoting a small aperture. Very good detail front to back and entire width. Kind of sepia looking, I expect it really was black and white.
I want two of those 18" steering wheels for mill knee cranks. I knocked about for some joke about shop overhead, but nothing worthwhile