brake calipers

As I prepare to upgrade my S1 to R6 forks, I began preparing my fleabay brake calipers by disassembling and cleaning while I wait for the new caliper seals. And as luck would have it, one of the larger pistons has some surface damage: The marks are toward the top of the piston. There is...

The other day I took off both of my front brake calipers and dismantled them in two pieces .. inside the brake caliper just underneath the brake pads there was a BRAKE PAD RETAINER CLIP I believe is the name of it... I am sure I had taken one off but I can't find the other one.. unless there was...