After more than 50 years in Ireland, the world’s oldest computer company has just got a facelift. Up until the end of last year, IBM’s Irish operations and dozens of subsidiaries around the world were mostly owned through IBM PDL Investments I Ltd (PDLI I), a holding company registered in Dublin and managed out of Amsterdam, where its immediate Dutch parent was based.  A series of recent corporate filings in both countries show that they are now held through IBM Investments Ltd, a company also registered at IBM House in Ballsbridge and controlled by the same Dutch-based directors, Jeroen Nolden…