The extra bold version of R. Hunter Middleton’s “Karnak” (produced in 1936 for Ludlow) served as the model for Bookkeeping JNL and is a companion to Bookkeeper JNL (the light weight version of this type design).
Middleton based his “Karnak” family of typefaces on the geometric slab-serif “Memphis”, which was designed in 1929 by Dr. Rudolf Wolf and released originally by the Stempel Type Foundry of Germany.
According to Wikipedia, “Karnak” "was named after the Karnak Temple Complex in Egypt, in reference to the fact that early slab serifs were often called ‘Egyptians’ as an exoticism by nineteenth-century type founders."
Bookkeeping JNL is available in both regular and oblique versions.