Here's a link to check out. If yours are the same as the ones in the pic you have a few choices.
You can:
1. have them welded
2. make up a set of brackets spreaders and rivet them in place. A hole as noted in one of the pics in the link would have to be closed (plated) by preferably welding, then rivet new bracket to that. If there is no hole you just make the brakets and rivet them on.
3. you might be able to find a spreader repair kit or a spreader kit and rivet them to the mast.
https://www.cruisersforum.com/forums...ld-144119.html