There are some factual issues with your post. The last part is just incorrect as the term predates WWII by a century and was created because the governor of Massachusetts, Elbridge Gerry (who was Vice President under Madison), signed a bill that carved out a convoluted political district favorable to his party that people thought resembled a salamander. The British did refer to the Germans as "Jerry" however and the term was applied to create many words such as as Jerrycan, which is a term still used to refer to a type of gasoline canister that was designed in Germany. However, Jerry-rigged also predates WWII as well and no one is quite sure about the origin, though it seems to come from the similar term "Jerry style" according to Merriam Webster dictionary. For all anyone knows it may just refer to some guy named Jerry (or something that shortened to Jerry) who was a bit of a shithead.
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