Just checked out the paperwork for the kits I bought this year.
You need Middy Nano core karp2 g 25 kits, they are £40 each part number is 20591.
Fishing Republic in my area do them.
A couple of other options to explore, Milo kits fit, the universal ones but you do have to cut them back quite a bit. The ones I have are very old I bought them at the Evesham festival way back.
One other option, Scott at Esselle made me a short extension for the Shimano number 4 that would accept Daiwa top kits, it was only £25, sadly for me it blew into Bollingey with my spare number 4 a few years back whilst I was netting a carp.