Faber-Castelle 67/87Rb Rietz (Additor)
|Slide rule/ Mechanical
|Country of origin
Purchased at a Value Village thrift store sometime in late March 2023. This slide rule has an addiator mechanical calculator on the back and came with its green leather slip case and the addiator stylus. I cannot seem to find much information about this model, I've found many picures of similar models, but none exactly the same as this.