I agree with the opinions of the above gentlemen. I have quite a few ancestors who bore various different clan surnames several generations back; but since I don't bear the same surname as my Forbes or Henderson ancestors for example, I wouldn't feel comfortable wearing a kilt of those clans' tartans, since I am not a member of those particular clans, even though I am descended from ancestors who were by blood; which is why I wear tartans that are associated with my surname, having inherited that through my direct paternal line.