My pool is around 20 years old and has 3 returns. They appear to be simply PVC piping with no threading whatsoever and no obvious way to mount anything.
One of the returns has a circular cosmetic face plate surrounded the pipe, but it is missing on the others (some crumbling plaster surrounding the outlet where the face plate was).
What are my options for installing eyeballs (or similar)? Most of the return fittings I've found have the 4-screw mounting rings or are designed to simply screw into a threaded PVC pipe.