30 Hp Jap Mariner 84'

[Culmination]

I have a 84' Mariner 30hp Japanese Model that needs a new inner exhaust plate. The old one is either warped or has a hole in it due to overheating from a bad water pump. Apparently this part is no longer made. Any idea where I can get one or what else I can do? Should I just scrap this motor?

Thanks,

Culmination