discussion/context:
https://www.dabbertgallery.com/artists/Teger/index.html
Marshall Oils are commonly used by photo students ... there once were Kodak Retouching Colors, which can be very subtle/realistic and were intended for gelatin or resin-coated surfaces (color or B&W). I found a set earlier this year...not cheap.
That diner image may tell us that, rather than using brushes (inherently not good for closely-defined sharp edges), he relied on knife-cut friskets.