I used PC-7 epoxy filler on two different wheels. Open up the cracks, clean really well and fill with the epoxy. Painted with top of the line acrylic enamel with hardener. That way you can color match to the interior or column. Glossy on the wheel, semi-gloss on the column and dash. Both painted about 10-15 years ago, still look great. I think Eastwood now sells a kit for doing this. Plan to spend 20 - 30 hours on the project but it is worth it.
