After discovering the above issue, the clio was off the road for the week whilst waiting for parts to arrive.
In the meantime I cleaned up the carriers to bare metal and painted them anthracite.
Genuine rear discs and brembo pads arrived from
@Kev@KAM. Went for brembo rears this time over the PBS as I've read there wont be too much difference and I will be changing front when going to brembo anyway.
Old discs removed and stub axle/spacers cleaned and refitted in the correct orientation.
The hub itself is pretty rusty but its solid, might clean it up at some point but definitely not priority!
Discs on, hubnuts torqued to 175Nm and pads refitted with a little copper grease.
Much better to look at than the flaking red that was previously on there! However, this wasnt the end of the story as I noticed brake fluid dripping onto my nearside wheel. Fluid was leaking past the piston 😭 I've since removed the caliper, removed the piston and seal and cleaned the whole lot with copious amounts of brake cleaner. Seal got a deep clean and some red rubber grease then it was reassembled.
I have ordered a caliper rebuild kit from ebay, which may or may not arrive tomorrow. I'm hoping my cleaning of seals has solved the issue! I'll check tomorrow if anything has dripped out.