Sorry, even with the better photos, the mei is still illegible. If I had to guess, I'd say its 廣 (hiro), but that single kanji by itself isn't a mei. A mei is typically 2+ characters for the swordsmith's name alone. Add to that another 2-3 kanji for the location, and another 3 kanji for the swordsmith's official title. Plus a few other kanji which could be added to the mei to indicate how it was made, or with what kind of metal it was made with.
So this one, seemingly random kanji, is still a mystery.