From Robert Peace this morning and shared with permission: "After a presentation I gave to the Victorian Rose Society in the early 80s, a member approached me to offer Gladsome which he had been using as a root stock. The cuttings duly arrived by post, wrapped in damp newspaper all cut and prepared for use as root stock. They struck easily. A lucky rescue as the variety was not in any other collection at that time!"
That's interesting in light of the 1936 'The Age' reference where one of the suggested uses of 'Gladsome', when Clark distributed cuttings, was as a rootstock.
Gladsome was also the name of a racehorse from the time of Lady Medallist in the second decade of the twentieth century. Although it's over twenty years before the introduction of 'Gladsome', Clark's rose, I can't help wondering if it might have been the inspiration for the name. Possibly 'Gladsome' was grown at Glenara for many, many years before the 1937 introduction.
