Hull or boat building instructions, doesn't matter.
I stand by my interpretation.
"Why else would they sell the plans separately? Sure they want you to buy their hull, but ...😉"
I have many plans for ships and boats of various types, including from John Lambert, and I don't think any of them have any building instructions included.
The former shapes help enormously of course, but even they can often be worked out or at least approximated. There are no thumbnails of the plan so can't tell if former shapes are included or not. If not the plan is not worth £15.50.
If they feel it is essential to buy both why offer them separately? Sure it's easier, and more lucrative for them if we buy both.
Cheers, Doug 😎