It looks to be a wonderful iris, that's obvious from the pics
! And you can be sure if we do nail down an I.D., we'll be sure to post it. I am amazed that what seems to me to be the same iris cultivar , has shown up ,at the same time, on two different forums ! There is another person on the HIPS forum who seems to have the same plant (bought from a commercial seller as an "unknown yellow"
), so that adds some "mystery" to the plot ,as well !.....Arlyn