OK, there are some interesting samples in there. I think it points pretty strongly to 守次 (Moritsugu).
The thing is, you have to also take into account the naming conventions of the time (what characters are suitable as names, what the other smiths of the time were calling themselves). So, for example, you wouldn't be likely to find a name like 尹寅, because it doesn't work as a name (whereas Moritsugu is a very plausible name).
And in traditional nihontō kantei (authentication), the name on the tang should be the last thing you should look at. In other words, the sword's shape, hamon, and steel grain pattern should tell you who made the sword, and the name on the tang should just be the final confirmation. Of course this is only a very idealized way of thinking about kantei, but to the sword purists it is still the only valid way of judging swords. So the shape should tell you the age, the hamon should tell you the location, and the steel grain should reveal who the maker was. That is the ideal, anyway. You have to study swords at a very, very high level to achieve anything close to proficiency in that kind of kantei. Anyway, this is all the long way of telling you to look at the sword, and then decide if Moritsugu makes sense as the swordsmith.
Just for my own curiosity, in the dictionary of Sosho writings, did they give a sample for Sada (貞) ?