Do you have your old correct one?

There’s a few other brand cars that have the same exact valve but use a different bracket. It may be cheaper to find and all brass NOS version for another car and modify your OE bracket to work. I’ve seen it done with riveting the bracket to the vacuum diaphragm. The valve section is just held on by two screws, IIRC

Like 67-69 Camaro? This was talked about years ago here… use both Moparts search functions