I have to go with Pearl on this one.
I am about 99% sure this one is 'Rameses'. It matches in every detail
that I can see; however, there is always a margin for error, I could be wrong
(but don't think so).
'Rameses' is a pretty common hand-me-down Iris (that's how I originally got
it, and it still keeps showing up in batches of "unknowns"), and it is a
survivor. Similar ancestry to many other equally hardy old TB survivors
such as 'Alcazar', 'Prospero', and many others.