As a follow up to above, I got a return e-mail from Wolff Springs. They don't have any plans for making the Roth Steyr springs, but if you send them the info on what you need: Outside Diamater, wire size, spring length and # of coils, they can check their database to see if they have anything that comes close.
I took my '07 out this weekend and put 25 rounds through it. In the first 5, 4 fed well, but the 4th failed to eject. From that point on, I had a failure to eject every other round. It actually seems to be getting better. I might make it through an entire mag some day.
As usual, it drew some looks at the range. The range master, who had never seen one before, asked me to drop the clip, when we went down to change targets. He gave it a close look when we went back to firing, but by that time I was out of ammo.