I don't have one for sale but am always looking.
I made a blank many years ago but never got round to deep hole drilling and rifling, may finish it one day though.
The big problem was ( still is? ), the length. I was never able to source one from existing models and still don't know of anything available ( anyone? ).
I have made a .25 'carbine' from a BSA rifled blank, thanks to others from here,
so that route might be a possible option for you to take. I believe that John Knibbs may be offering replicas for sale again soon?
atb
Carl