Hemmi model P40RK

I'm not aware of this slide rule in any Frederick Post catalog.  I suspect that, at least sometime, it was what you got when you ordered a Post bamboo model 1447.  But when would that have happened?  The 1967 date code on the specimen shown below implies 1967 or later.  I have arbitrarily asigned dates in the cross reference spreadsheet.

This is an "open body" slide rule.  The full length of the back of the slide (except what is hidden behind the end brackets) is visible.
 

Date Code "RF"  (June 1967)