Are these for disc brakes?

Those are the brackets that need to be reproduced badly, but are not.
At one time in the past, a member here on this forum did reproduce them.
He sold out of every one that he had.
Would like to see him do it, all over again.
But more than likely the 2024 cost in doing that, is a major deterrent.
Then the guys time to advertise, keep up with orders, go to the post office, profit margin, just ain't worth it anymore.