5-Inch Slide Rule with Folded Scales
Frederick Post model 1445  [1936-40]
Hemmi model 34p
Appears in 1936 Catalog and Price Lists through 1940.
No specimen available

Top edge:
Bottom edge:
Back of slide:
Back of rule: 

This page is from the 1936 (18th Edition) Post Catalog 

Catalog says "extra thin" but surely same as Hemmi 34p which is NOT thin.