The bulb socket in my Hayward SP-580 12v rusted out. Even though there appear to be screws connecting it I've read you can't just replace the socket. If I'm wrong please let me know. That brings me to my main question. Is there a cheaper alternative to replacing the fixture than buying an OEM Hayward fixture? They seem to be scarce and expensive. If not, what are the compatible OEM part numbers? I assume my light niche is an SP-600. Thanks for any help.