The Scots Kirk in Paris had been unused throughout the war; lack of maintenance led to the church having to be rebuilt during the 1950s. To help pay for the rebuilding, in 1957 his autobiographical account of his extraordinary wartime activities were published as 'The Tartan Pimpernel'. The 1950s building proved to have serious defects and had to be again rebuilt in the late 1990s. Donald Caskie's book was again reissued to raise funds.

      After completion of the Rue Bayard church renovation, Donald Caskie answered the call of Greenock presbytery when on the 11th January 1961 he finally returned to Scotland to become minister at Wemyss Bay and Skelmorie on the Firth of Clyde. He never married and retired through ill health to Edinburgh in 1968 and moved into a private club in Edinburgh from whence he did pulpit supply and fulfilled many requests to speak at a wide variety of functions. In early 1983, and in poor health, he moved into the care of a younger brother, Neil, in Greenock and died on the 27th December 1983. He is buried with his parents at Bowmore on his native Isle of Islay. Various personal artefacts, including his wartime medals can be seen at Kilarrow Parish Church, Bowmore.

      It is exceptionally difficult to compile accurate data on wartime escape. However, expert researchers in the field have estimated that during World War II, somewhere in the region of 3,000 British and Dominion service men managed to get out of occupied Western Europe and back to UK shores. The majority of these would have emerged from France. It has been estimated that Donald Caskie had an involvement in the safe return of approximately 2,000 men, roughly two thirds of those who made the home run from France. This figure is all the more remarkable given that he found himself in this role with no preparation and nothing to trust in but God and his own instincts. Many of those Donald Caskie saved were in the forefront of the campaign from D-Day to VE-Day.