MPC can be dated by the first two digit of the series number. In this case, the 46 of 461 indicates that these were issued starting in 1946, and the 1 notes that it was the first series (there was no second series for this note).

The offical release date was Setp 16, 1946 in the European tjeater and Sept 30, 1946 for the Packfic theather.

These notes were used in Austria, Belgium, ENgland, Germany, Greece, Hungray, Iceland, Italy, Japan, Korea, Morocco, Netherlands, Philippines, Ryukyus, Scotland, Trieste and Tugosolavia.

These notes were withdrawn from use in March 10, 1947 and replaced by series 471.

Hope this information is of some help.

John