5-inch Universal Slide Rule
Frederick Post model 1451 [1936-40]
Hughes Owens model 1762
Hemmi model 34R

No specimen available

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

This page is from the 1936 (18th Edition) Post Catalog 
The term "Universal" is new and seems to be Post's term for rules with the "improved"
Mannheim scale set A [B, CI, C] D, K.  Hughes-Owens used the same terminology. 

 Although this catalog page implies model 1451 had scales A [B, CI, C] D, K  I don't think it did have a K scale.   Post model 1444K (also a five-inch rule), which did have the scale set A [B, CI, C] D, K was introduced just a couple of years later.