Full Details

Name and Model Number Wichmann
Country of Origin Germany?
Date of Manufacture  
Front Scales A/B,C/D
Back Scales None
Scale Length 125 mm
Type of Rule Slide Rule
Construction Card and steel
Area of Use Generic
Rarity RRR
Donor Collection of Colin Barnes
Match Number 85

RR = Rare -- 1 of 25 collectors has one; it may take a year to find an example in the marketplace.   
RRR = Very rare -- only very few known to collectors; may take several years before one comes up for sale.   
RRRR = Extremely rare -- a museum piece; unlikely that an example will ever come up for sale.