WFO 141 Amendment 1 prohibited distillers from using grain for beverage spirits without Agriculture Department authorization effective September 1, 1945. WFO 141 Amendment 4 and WFO 141-1 Amendment 3 ended the authorization and fixed-total-use quota regime effective December 1, 1946, while retaining narrower commodity-specific restrictions.
Start and end are verified in complete, contemporaneous Federal Register issues: 10 FR 11381 and 11 FR 14065–66. The 1948 Senate account independently describes the intervening Agriculture allocation period.
Use September 1, 1945 through November 30, 1946 for the federal authorization/allocation framework. Do not say every grain restriction ended December 1, 1946: wheat, certain corn and rye, feed-recovery, reporting, and enforcement provisions continued.
The paired Agriculture instruments provide exact legal bookends; the Senate account supplies retrospective administrative context.
Publication-safe when December 1, 1946 is described as the end of total-use allocation, not total deregulation.