Tyndall's experience with
mergers and acquisitions earned him the nickname "Take-over Tyndall" in Irish business circles. He absorbed many of the employees of wholesalers who closed down (Hugh, Moore & Alexander, Shirley Spence & Belford, McMaster, Hodgson, R. Jones & Co.), and introduced a bonus
incentive scheme, and a scheme of non-contributory pensions for employees. He was behind the first initiative of an Irish wholesale group to establish a
bonded warehouse to expand their wine and spirits business. After his father's retirement, and in collaboration with his older brother William, he expanded the Tyndall interests to include retail stores, through joint ventures for
self-service stores across Ireland. They resisted a 25%
takeover bid by Irish businessman
Tony O'Reilly in 1971. Eventually they sold AWL to Joshua Watson Ltd., and Dave Tyndall Jr. joined its board. It was later taken over by Irish Distillers, who were later taken over in 1988 by Pernod-Ricard. William retired in 1980 and Dave retired in 1984, after fifty-one years in the grocery business. ==Aviation interests==