Hi Craig.
The discs I have are Nissan Almera N15 2.0 GTI rear discs.
They have them on
www.brakeparts.co.uk 15.60 (ex vat) each 258mm. But I thought the MRG ZR 1.8 discs would work as they are 260mm. But not tried them.
But I would strongly suggest you contact Marlin as they could well have made changes to the hub that is on mine. And could be different.