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You could disassemble it and go get it TIG welded which is probably a wise move.
Failing that it's a new lower mast section, but I'm presuming it's a 2 piece mast?
Failing that, leave it & when it fails claim on your insurance & get a 1 piece mast as an upgrade which is miles better.
Looks like age related wear n tear so the insurance comment is a bit 'tongue in cheek', plus a new mast is >£1k probably so the boat needs to have the value there to warrant a claim.