Get someone to fill it with braze and then get it rechromed. Flick Brakefree a message and see if it can be done and for how much. He might be able to collect the fork when he’s in town soon (cos hes from Can-bra)
You could weld it up and file it smooth but the chrome will be shot. How about - Aarons’s Body filler suggestion or fill it with quick steel epoxy metal putty (this stuff is amazing for those who have never used it btw). You can shape it easily with your fingers and it takes a while to cure so you have plenty of time to get it right. light sand/file and paint the fork crown ONLY - leaving the blades and fork ends chrome.