Finally got the new rear brake fitted.

I finally ordered the Shimano BR650 rear brake from Wiggle and fitted it on Friday so no more Tektros and matching brakes again!

As it happened, the Aztec road system pads on the front were practically worn out so I fitted the Swiss Stop green pads at the same time in the Shimano cartridges. I've not ridden them in wet yet but they're very good so far in the dry.