That part that's broken off is cantelevered out in space and is unsupported too. It's strong enough if everything is adjusting and working right, but when a convertible starts leaking around the front, the first thing people do is tighten up the hooks and that breaks (or cracks) these things.
No way JB weld will hold. I considered TIGging it but I don't even think that would work.
Richard, you described the one you sent EXACTLY! I wasn't complaining. It just threw up question marks about how it came to life.
I called an investment casting company and asked if they could use my existing one instead of wax, to dip in the slurry. He said yes, but they fire the ceramic at 2700 F or so, and it would cause all kind of problems at that temperature, trying to preserve my metal. He suggested I use my part to make a silicone female mold for pouring one.
Sounds pretty simple but I don't want to do it if I don't have to. He did tell me the right product to buy to make the mold. We poured aluminum castings in High School 30 years ago. Mostly sand-castings.