I checked a few places but haven't found any that are selling Song of Erin. It is an historic (older than 30 years) so that makes finding it a bit harder. Hopefully someone will have a lead for you.
"The chimera is a one time happenstance event where the plant has a senior moment and forgets what it is doing." - Paul Black
Plodder!
I looked up the hybridizer for Song Of Erin: Lura Roach from Los Angeles, California. You could try contacting Region 15 chapter of the American Iris Society (which includes southern California) and see if they could provide any leads. https://www.region15ais.org/
Plodder!
