How can you tell Honorabile from Gracchus? is there any other that might get easily confused??

We have an old yellow iris with dark falls which I have tentatively as Honorabile. It has bright yellow, um, standards and bright yellow fuzz (beard? stamens?). It is similar in appearance to ones identified here as Honorabile but not quite as faded on the lower left and right of the falls... hope to post a photo soon as they are just coming into bloom.

We are told our house was built 1840; there were major renovations in the 1910's and iris leaves appear in some photos slightly later.