The Three Railway Engines is the first ever book about The Railway Series published in 1945. However, when it was first published, it had slightly different illustrations as William Middleton originally drew them. They were all lost when Clarence Reginald Dalby re-improved new ones.
In 2005, some of the Middleton illustrations were uploaded on a Thomas the Tank Engine fansite. More were shown on the Sodor Island Fansite in 2007 and 2008. On December 2nd 2014, TTTE Wikia user SkarloeyRailway01 finally uploaded the original versions of all these Middleton illustrations.