10-inch Plastic Slide Rule
Frederick Post model 1452P [1945]
Mfd by Grafton Plastics


Top edge: 0-10 in (slant)
Bottom edge: 0-15 cm (slant)
Back: USBS Circular 47.

Rule is prone to chip when dropped. 



 

Excerpt from 1945(?) Price List
Second price listed is per dozen.
 

Manufactured by Grafton Plastics of Grafton WI who marked the rules with the retailer's name (Post, Dietzgen, Bruning, Compass and others) and shipped them to retail distributors.  Post rules were shipped with cursors marked "Frederick Post Co."  Many of these slide rules survive without any retailer's name or model number on the body but Post rules can be identified by their cursors.