Can't find Steel Ram blueprints - am I screwed? (Belerion)

[2roadsdiverge]

I know I received the blueprints for the Steel Ram after I saved the kidnapped villagers. I saw the popup but then got jumped by wandering NPCs and missed what it said. However, when I went to build the ram I couldn't find the blueprints in the Sailing menu (under Figureheads, I assume). I thought it might be under Smithing, or even Tinkering, but not there. I even went to the Shipyard where the NPC brags about how good he is at figureheads.

The only thing I can think is that I accidentally sold the blueprints somewhere. I can't believe I would have done that, but I've looked in my ship's hold, the camp chest, and the travel post chest. I don't want to sail to every merchant in Belerion, but that seems to be my next step, if I did sell the blueprints.

Am I screwed? Without the Steel Ram, I can't upgrade to the Akhedian Steel Ram, right? I don't really care about any achievement for getting all figureheads (well, I do but will forego it to be able to progress the story). I'm just stuck on 60% and can't escort the dude to the cursed isle without that ram.