"The Thing-Ummy Bob" is a 1942 song which was written by Gordon Thompson and David Heneker which celebrates the production line worker of World War II making components for complex weapons to win the war. Its chorus is
A thingumabob or thingummy is an extended form of the word thing which the Oxford English Dictionary records being used as far back as 1751.
The song was popularised by performers Arthur Askey and Gracie Fields.
References
The Thing-Ummy Bob Wikipedia(Text) CC BY-SA