Asturian Tree Cabbage

Apparently the seeds for this can only be bought from Real Seeds? Real Seeds are out of stock so this is a plea for a few seeds off anyone who has any?
If I could just get one plant I think it can be propagated from cuttings, but getting that one plant is harder than it seems.

I will gladly pay for the seeds and P&P. Or if anyone knows where I could purchase some, that would be better.

I have "Couve Galega - Portuguese Walking Stick Cabbage" if that's any use?

Many thanks for the offer Danny. I have grown walking stick cabbage before but its not what I am really after. Good luck with yours though.