[John Bartley]

You can try all sorts of things. It is very likely that none of them will be permanent.

You have 2 layers of broken veneer and poor adhesion. Differences in humidity and temperature are likely to open this radius split again over time.Replacement of the veneers and inspection/repair of the underlying structure are the only long term fix.

I second what Russ said, I've tried the short cuts, they look good for maybe a year or more and then you are right back where you started.
Regards
Arran

I agree. The best and maybe the only permanent repair to to remove the existing veneer, clean up and repair the structure underneath it and re-veneer. To get the columns to match (L&R) you will probably have to do both.