Hi all-hope summer is going great for y'all.

Maybe someone can advise me. I have 2 returns.They are plumbed flush to the pool wall and the eyeball returns screw into the return until they are snug against the pool face. It appears that the thread is rusted off the female receptor on one of them and the eyeball won't stay on. From the pump going through the cement floor in the pump house , the return line is a thick black plastic pipe. The end that comes flush to the pool wall is steel of some kind. Any idea as to how i would proceed to fit an adapter in there so that I can screw in the directional eyeball ?Are there eyeball returns with a straight end on them that i can push in there and then screw them on to the wall ?


Here's the eyeball type i have-on the right in the pic.