These are the 1/2400 scale Medieval cogs made by Bill Lamming and introduced, I think, at the same time as his medieval Campaign rules. I never had any back in the day, although BL sold them for pennies. They are now available again from Tony at ERM but cost a bit more these days.
I obtained these - all vintage castings - in two lots, in the last three or four motnhs. One set have a small cast on sea base, the other lot just a plain hull. I have put both types on basetexed pennies, to give a robust and protective sea base.
I'll add a bit of context to this post in the next few days.