This is a fresh examination of the 'intelligence' gathered for the great train robbery. The suggestion of an Irishman ('The Ulsterman') was simply part of a package created by the robbers in time for their release from prison and to contribute to the subsequent book - everything since has compounded the 'mystery'. Gordon Goody was one robber who 'met' The Ulsterman and speaks highly of The Ulsterman's information, but this information could easily be found elsewhere, and some of it is incorrect. So who else might have given 'intelligence'? One by one, other 'suspects' are identified and discounted, but with evidence for their defence. To use the metaphor 'hidden in plain sight', one can identify another 'suspect' with all the attributes The Ulsterman was said to have. If the reader is willing to look at the evidence afresh, it's necessary to consider not what the robbers et al have said, rather what they haven't said. The robbers were dishonest men who frequently lied - but writers and commentators have followed what they have said. And it hasn't really led anywhere.
To unravel the yarn presented, it wasn't a senior official in either the Post Office or British Rail. It was an 'ordinary thief' with an extraordinary ability to blend into the background, and have fingers in a great many pies. Let's expound the myth.