I have 7x of this style return, plus 2x 3/4" female thread ports that look like a return should be there. They're all cracked or missing. I took this part into our local pool store and he said they didn't have any returns this small. He also tried to convince me that I needed to remove part of the pipe that's in the wall. Not happening.
I think I just need this 8-sided nut plus an eyeball for each return, and I can screw them into the existing male thread jutting out of the wall. It looks to be about 1.25", but a 1.25" pipe thread is too big for the nut.
I browsed around online and couldn't find any replacement parts that look this simple. Everything looks like a multi-part diverter/return assembly.