Revell Europe and Pyro both made carrack kits once upon a time. But they represented (not very well) fifteenth-century or later vessels - i.e., post-medieval ones. (The "medieval" period is generally said to have ended with the beginning of the Renaissance, in the late fourteenth century.)
As for hstry's list of kits - I can offer the following personal observations, but please bear in mind that some of them are based on my extremely unreliable memory. Also, several of the kits on the list are reboxings of other companies' kits; in some cases I'm guessing at which ones. And let me emphasize again that these are personal opinions, with which anybody else is of course perfectly entitled to disagree.
Heller's "William the Conqueror Ship" is a modified reissue of the same company's alleged replica of the Oseberg Ship. As the Oseberg Ship it's an awful, proportionally-distorted travesty; as a Norman ship it's a sorry joke. Nobody knows with any certainty what the ships of the Norman invaders looked like; the one and only primary source is the Bayeux Tapestry, which gives only vague, highly stylized side views of them. But it's generally agreed that they didn't look like a Viking ceremonial barge (which is what the Oseberg Ship is believed to be). I recommend avoiding this one.
The Zvezda Greek and Cartheginian galleys are, I believe, reissues of Heller kits. People who are more knowlegeable than I am about ancient galleys don't take them seriously; among other problems they're far too short for their height and breadth. The whole subject of the ancient war galley has undergone serious rethinking during the past twenty-five years or so, largely as a result of the reconstructed Greek trireme Olympias. Every plastic ancient war galley kit on the market, so far as I know, was originally released before the Olympias was built. (It should be noted that some eminently qualified scholars have big reservations about the design of the Olympias. But it's been pretty firmly established that the old Heller kits are grossly out of proportion. There are several threads about them here in the Forum; the comments of a member named JWintjes, who knows far more about such things than I do, are particularly worth reading. He suggests that, by slicing the hull of a Heller galley in half and inserting a section taken from a second kit, it might be possible to make a reasonable model. But I don't know that anybody's actually tried that.)
I think the Smer "Viking Dragon" is the ancient Aurora kit from the 1950s. If so, it's a great toy for kids but that's all. The people who designed it apparently did no research whatever about Norse shipbuilding. (They were working in the dawn of the plastic scale modeling era; their intended purchasers didn't care much about historical accuracy.) Frankly I wouldn't mind getting my hands on that kit, as an exercise in nostalgia; I don't know how many times I built it when I was in elementary school. But as a scale model of a Viking ship - forget it.
I think the Smer "Drakkar-Oseberg" is a repackaging of the Heller kit that was similarly labeled. (I may be wrong about that one; I can't recall ever having seen the Smer kit.) If so, forget it too.
I think the "Conquistador Ship San Gabriel" by Zvezda is also a reboxing of a Heller product, which in turn was based on the hull and other basic components of the Heller Santa Maria. I've only seen photos of the Heller "Conquistador," but on that basis it frankly looked to me like a piece of junk. The Heller designers in those days (the early seventies) appear to have been immensely talented artisans who possessed only a vague understanding of how sailing ships worked. They were notorious for making "new" sailing ship kits by slapping new parts on old hulls, thereby coming up with shapes that sometimes looked believable and sometimes didn't. This one, to my eye at least, didn't.
I have the Academy Roman Warship. It's a reissue of a kit from the late, lamented Japanese manufacturer Imai, and as a piece of plastic kit engineering it's a masterpiece. (Imai was, to my knowledge, the only company that's ever figured out how to make reasonable-looking blocks and deadeyes in injection-molded styrene.) It's probably the best of the plastic ancient galley kits. It does have some serious problems, though, starting with the stated scale - which is far too small. And for some reason the openings for the oars in the outriggers don't have oars in them. (Imai also made a "Greek galley," which shared many of the same parts. The "Greek" version had oars sticking out of the outriggers - but not through the oar ports beneath them. Weird. I think these two kits may have been among the first in the Imai line, which eventually included some of the best plastic sailing ship kits ever.) If I had to pick a plastic ancient galley kit on which to base a serious scale model this one probably would be it. But it's "pre-Olympias."
My senile brain has just dredged up one other plastic medieval ship kit. Imai made a Viking ship. But it was extremely small - probably too small to be of much use in hstry's project.
I've only seen the box art for the Zvezda "Medieval Lifeboat." It looked reasonable - though I question whether the term "lifeboat" was in use at the time. (Lots of people use that word to describe any small boat. That may be what's going on here.)
I fear that's a rather depressing list. The medieval period just isn't well represented by the ship model kit manufacturers - plastic, wood, or otherwise. The good news is that two of the relatively recent kits, the Zvezda cog and the Revell Viking ship, actually are nice kits. (Dr. Wintjes pointed out, in another thread, that the deck planking of the Zvezda cog is "laid" longitudinally, whereas the deck planking of all the few surviving real cogs is laid athwartships. But he acknowledges that our knowledge of cogs isn't enough to brand Zvezda definitively "wrong.") I'd have trouble recommending any others.