Thanks, everyone, for all the suggestions. It sounds like a different BB spindle is the easiest fix. I just wasn't sure that it would increase the chainline (which I guess is what I would need).
Here is a photo of the chainrings from their website. It doesn't show very clearly what is going on around back, but if you look closely, you can see the protrusion. Also, because of the unique mounting mechanism, the bolts will be moved inward with a smaller inner chainring.
My bike (loosened the crank bolt so it is no longer scraping the frame):
