Frederick Post models 1464-70  [1925-1930]
 
Post Ritow model 1466 appeared in the 1925, 1927 and 1930 Post Catalogs.  Ed Chamberlain has the only known specimen of  model 1466 [1925-30].

 Post Ritow models 1468 and 1470 appeared in the 1925 and 1927 Catalogs but not in the 1930 Catalog.   No specimens of these rules are known.  My guess is that they were never actually available. 

Retail prices (without leather case) from September 1927 Price List:
        1464: $10.20
        1465: $11.40
        1466: $25.20
        1468: Blank
        1470: On request
        (add $1.05 for leather case)

 

The page shown here is from the 1927 catalog. 
For more information on Herman Ritow and Post "Ritow" slide rules, click here. 

These slide rules were made by Koch, Huxhold & Hanneman in Hamburg.

 Rules identifed as "adjustable" use the DRGM 192052 friction adjusting mechanism.