The left side plastic tank can be replaced by a radiator shop.
It takes a special crimping tool, so it can't effectively be done at home.
I had one done at a shop in Tulsa several years ago - lasted another 5-6 years before the radiator gave out. If your radiator is not in perfect shape, or is original, then probably not worth it. However, the replacement Behr I bought is like a piece or tinfoil compared to the robust original Behr. but, it's working okay.
Yeah, replacing it is really easy.

DG