Would something like this work? It has a 3 tab clamp on one side, center tab on other way. Not sure if that would stress it out and break too or just not sit correctly since you’d have the heatsink on backwards technically

It’s been too long since I seen these type boards. Heard of someone using a dremel on the broken area around the tab to make a tab but that seems extreme and no way back if it fails.

https://www.ebay.com/itm/115876556377