This tool fits into the slots inside a 1-1/2" MIP thread pool "eyeball" (aka nozzle) so you can unscrew or screw it in.  Yes, it fits a Hayward SP1419D!

Note: Make sure to print this in a filament that's reasonably strong and rigid.  Those old eyeballs can get calcified and be real tough to remove!  I printed the (black) example in AmazonBasics Premium black PLA and it seemed strong enough.

Tip: If you can't unscrew the old eyeball with this tool (it just starts to bend) then you'll need to break out some self-adjusting pliers (e.g. Robo Grip or similar) and really go to town on the old eyeball center part.  I had to break off a bit (notch) of the threads on mine and then whack it with some scrap wood and a hammer to free it from it's calcium prison.  Of course, I used my tool to screw in the new one =)

Don't screw in the new eyeball in too tight!  Also use some PTFE (Teflon) tape on the threads to make it easier to unscrew in the future.

Note: For commercial use just ask! I want folks to ask permission so I can know where it's being used.