The collection mainly consists of Heslop's unpublished works. Apart from a typescript of the source of his posthumous Out of the old earth, there are no copies of his published works. How much material was destroyed by the bombing of his house in 1940 is not clear, as some other items in the collection predate this, but the copies ofhis works appear to have been written or at least copied after the Second World War. Some have been submitted to publishers, as can be identified by their card bindings and agency stamps, and these include works on James Mather, and several novelsset in the north-east. There is also a work set in world split between the Second World War and the Monmouth rebellion, perhaps reflecting his move to the south-west, and a play set in biblical times, as well as a study of the British politicalestablishment written with Bob Ellis as a sequel to their study of the Abdication Crisis. This work seems to lead into the book, or books, that occupied much of Heslop's later life, a study of Marx. This exists in several states of varyingcompleteness, to the extent that it becomes difficult to identify if it is one work, and if so, how it changed over the years. One of the latest items in the collection (HES/C378) indicates that nearing the end of his life Heslop tried to put hispapers in order, which may reflect some of the difficulty in understanding the exact structure of this later material.
There is some correspondence from the 1920s, notably from Zinaida Vengerova-Minskaia, who translated Goaf into Russian, and a few letters and press cuttings of reviews about Heslop's novels. The letters frm Bob Ellis form the largest group, and show clearly how the two men collaborated and shared ideas in the 1950s,although there is only one example of Heslop's side of the correspondence. Letters from Victor Collins (later Baron Stonham) reflect another long-standing friendship and a continuing political discussion. A group of printed pamphlets were mainlyproduced in or reporting on Russia, and the photographs all seem to be of Russian origin from the 1930s.