You can try contacting Bill LeGall at Miller Sound (
http://www.millersound.net) and see if he has any he would be willing to sell you.
He specializes in repairing the Infinity IRS line & owns a pair of Infinity IRS V. He had a good supply of parts. I brought my IRS Beta woofers there 10(?) years ago to have the foam surrounds replaced & have them dynamically balanced. He did an excellent job, & I recommend him highly.
He is a nice guy, but can initially come across as a bit brusque. If you treat him flippantly, he just might "show you the door"...