It's not an uncommon problem Kevin. The fracture is caused by high frequency vibrations from the chassis, suspension and wing.
Get it repaired (welded) or replaced asap otherwise you risk damage to the wing due to lack of support.
Personally, I'd go for welding as you'll be able to get it done quickly and you'll probably not have the problem of any mounting holes being miss-aligned with a new one. The cars are handbuilt and brackets such as these are often 'worked' to fit.
