Very pretty!

Here is a link that might be useful: old iris

mrtoad ~~

Very difficult with a rain-bloom. Maybe next year you be able to catch it dry. The more pics the better.
These two looked the closest of what I've seen:
Magnolia (link below, Stevens'39)
Real Challenger (daves garden pic)

The following didn't seem to be as good a match:
Alice Harding (standards & beards seems darker yellow than yours)
Ecladore (hafts and beards seem darker yellow than yours) (name included for others searching for historic pale yellows)
flavescens (standards seem to have more color and haft veins more pronounced than yours)

Here is a link that might be useful: http://historiciris.blogspot.com/2008/04/tall-bearded-iris-magnolia.html

iris_gal - thanks so much for your help

mr toad

You're welcome.

Oops, just saw another one that looks quite similar - Ingeborg, Goos 1908.