We had a horimono post not long ago, if someone wants to search it out. It had many pages of good examples...
I think it's important to keep in mind that not all legitimate original horimono were of the quality of Yanagimura,Yoshitane, Nobuhide, Sadakazu, Sadakatsu, Ikkanshi Tadatsuna, etc. Personally, I don't know what to think about the OP's sword... to me, the hori almost looks unfinished . Also, you have to consider that after multiple polishes, the shinogi-ji and ji might not have the material removed perfectly evenly, which could lead to distorted looking horimono, so...
Eric- I remember seeing that sword for sale as Masahide (I think), but the hori don't really remind me of Yoshitane, or Nobuhide, from what I have seen - but they are some of the nicest horimono I've seen, so I wouldn't be surprised if either of those guys did them... well, whoever it was did a hell of a job. Do you have any ideas on the horimonoshi?