As suspected, it's the handbrake seal

I have enquired with a couple of factors and they are readily available, the thing is I know they will be silver, opposed to gold (as replaced as a pair) and given mine is new, I would like to replace the seal, if possible.

Ridgey, this is where the calipers were from, incidentally.

I have found a kit for one caliper, usually these are sold as a pair, so not too expensive.

My concern is the absence of the special tool (12-007 to be precise) used to compress the spring, I am aware you can improvise and use a socket in it's place for example.

I have a G-clamp, therefore I just need a pair of circlip pliers, right?

Martin