|April 1932 Price List to accompany 16th Edition (January 1930) of Frederick
Post Catalog. Both pages that list slide rules are reproduced below.
There was no page for "New Items" in this price list. I believe that all slide rules in this price list were new Hemmi models replacing KHH. Twelve slide rules are listed with prices. Nine of the twelve listed rules have the same model numbers as Hemmi rules in the next available catalog (1936); their prices are appropriate to their 1936 catalog descriptions. Until further information I will assume that these nine rules are indeed the same as the corresponding 1936 Hemmi slide rules.
The remaining three of the twelve listed slide rules are four-inch "vest pocket" rules. Two (models 1447 and 1447M) were renumbered 1440 and 1441 in the next catalog. (Specimens marked "1447" and "1447M" exist to corroborate this.) No specimens marked "1447A" exist but it's probable that it was the same rule that was renumbered Post 1437 in the 1936 catalog.
Many slide rules from the previous (1930) catalog, including all "Ritow" rules were "out of stock." The era of KHH rules appears to have ended for the Post Company.
When did Post switch from KHH to Hemmi? Before the date of this Price List (April 1932) and after the April 1930 Price List. The very first Hemmi duplex rules distributed by Post in the United States came with a 9 x 12-inch English-language instruction manual printed by Hemmi, not Post. It was dated 1931; that seems a likely guess for the date of transition..