Thanks for those, very helpful and it's good to see the end of the phragmocone. It would have been a whopper!
from there do show very clear growth lines - in fact, the preservation is generally excellent and sometimes may even involve some soft tissue preserved as pyrite on the surface. This is presumably down to the anoxic sea floor conditions at the time.
Here's a phragmocone with protoconch from there, and growth lines.
Excellent. Speaking of Phragmocones...found this one at Saltwick. I was told they were common but again I've never seen one as big and in such good condition as this even on-line (they all appear squashed). It is just over 8 cm long by 3 cm wide at base but there is more still in the nodule. Could it be from Acrocoelites.