David Clark Headset spares

After years of balancing on my head, my cloth helmet finally had to be separated form the headset for a long-overdue trip into the washing machine.

I had to nudge off two tiny circular retaining clips ( 5mm diam ) to slip the holding bracked away from the headset. My re-assembly must have been faulty, as the microscopic clip pinged off again, and is somewhere on Halton airfield.

Anyone know where to readily get spares in the UK ?