Going back to Robert Casey, his WW1 service record has a copy of 2 letters he wrote in 1938, which you may have seen. One letter is dated 28th Feb 1938, which would be during the Spannish Civil War period.
He wrote as a member of the Old Contemptibles, requiring confirmation that he had been issued with the 1914 Star Clasp. In another letter, he states that the Old Contemptibles required a written statement that he was entitled to wear his clasp.
There was a branch pf the Old Contemptibles in Stockton and members had to be entitled to the clasp. They were entitled to wear their medals at their annual memorial parades. There was one in 1938, at Ashbrooke, at which the Sunderland Branch were part of the parade (reported in the Sunderland Echo 29 Aufg 1938, p.3). Preseumably his letter was in advance of this parade.