The Grady tale also appeared in “Classic Motorcycling” No. 18, wherein Grady recounted his tale to Paul Reed in 1981. Included was a route map around the continent. It has a bit of an introductory and postscript but the part about the trip is a much abbreviated account (with the portion of the carter with the TS model slung under the wagon miss-printed twice) compared to the version credited to the "Motor Cycle", June 11th 1925. Much of that abbreviated portion of the actual trip is verbatim to passages in the longer version, indicating that rather than printing the complete tale as contemporarily related by Grady, the author relied on extracts of the older publication. I do not know when this version was printed, as the date does not appear in the photocopy I have. But it does mention at the end Grady died in 1987, so it must postdate that. It also mentions the trip was sponsored by Douglas Motors, Bates tyres, and the western Australian agent Armstrong (of Freemantle?) to promote the new all chain drive CW model. It is said the machine was sent back to England, and later displayed in the Douglas museum, what ever that was. The current whereabouts of the machine was unknown.
In the "Motor Cycle" version, in the portion “A Word from Grady”, it refers to the tale as “Previous to the historic attempt recorded in this booklet…” suggesting it was publish as a monograph. Probably by Douglas; like they did after a win in the TT. One wonders if any copies survived of the Douglas-Grady version.
As mentioned in this thread, it was also reprinted in the New ConRod a few years back. But exactly when and which version I can not recall. Unfortunately the NCR is not indexed, so looking up such items is tedious.