"Jury-rigged" is an 18th century term that refers to a sailing ship of questionable construction, and/or a cat tree/condo. This ambiguity makes it undesirable for modern use, and largely irrelevant.
"Jerry-rigged" is a 19th century term that refers to anything of crude or improvised construction. However, it could also be considered a derogatory term for something made by (a) German(s), which makes it politically incorrect.
Therefore, "Jimmy-rigged" is the only currently acceptable term for a crude and improvised piece of shit that was cobbled together by an inbred moron.
Did you know that if a train started from New York to Boston at 9am, travelling at 50mph, and a second train started from Boston to New York at 10:45am the same day, travelling at 43mph, neither of them would have a buffet car?