Ok, so the bike has now been split!
@_Leon is taking a few bits, pending collection this evening. I've updated the original post clarifying what's still available.
@Hefty & @The_Merchant - the frameset is still available.
I'd prefer to sell the frameset with the headset and BB fitted. It's £350 for the frameset, £25 for the near new Tange Seiki Levin Alloy 1500 NJS headset and I'll throw in the Shimano UN54 BB for free.
Thanks for all the interest so far.