Spending money on Aer Corps equipment always terrifies Irish Governments. This Learjet was always the second fiddle to a Gulstream IV until that needed major overhaul in the Gulfstream factory. The Government dithered over whether to spend the required funds on the airframe until Gulfstream told them to make up their mind, whereupon it was sold to Gulfstream for apittance along with various spares (including an engine), who then overhauled it and sold it at a massive profit.
That Gulstream was supposed to be replaced by an A319 a few years earlier, but the public backlash ended that. This LJ likely has the most cycles of any in the world (like the Gulf IV did).