Having just stripped & cleaned up some of the later front Caparo calipers I was surprised to find the original spring clips had lost their temper (heat treatment) and gone quite soft

This is worth checking next time you have access as the later dumbbell style pins are held in place by the pressure of the spring clips

Saggy clip is the mucky one (new pair on the right)

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This is location in the caliper, showing how they retain the modern brake pad pins

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Jon M