O-D - 17 clasps issued for the 1918 GSM. The only Brit recipients of the 'Southern Desert Iraq' clasp (1928) were from 30, 55 and 70 Squadrons, RAF. The newly announced 'Cyprus' clasp to the 1962 GSM will bring the total to 14 clasps for that medal (you are quite correct up to this date teeters).
You are right about the MC, of course, but it continues to be available to RAF officers when operating on the ground. There were a number awarded to escaped RAF POWs during WW2, and of course quite a few have gone to RAF regiment officers. When I was at Catterick we had a squadron leader who had won the MC in Aden, and even more unusually a wing commander who sported the ribbon of the MM which he had won as a corporal during WW2.
Re Cold War and Cod War - how about two new so-named clasps to the GSM - they'd look quite good together!