POR 15 makes a steering wheel repair kit, and I've heard good things about this type of stuff: http://www.plastexexpress.co.uk/ but have never tried it...

I would imagine you may have to head your wheel around the hub area to try to reshape it. Clamp it some how and let it cool. (perhaps adding some epoxy to "glue" it in place beforehand?)

Then start from there... Keep us posted on how things go!

Brett!