have perfectly ok sunsaver pool light except o-ring is severed. Tried to find online but it is part 05101-4590 (purex) or 3510-34 (sta-rite) for pre-1999 lights. O-ring is now obsolete and unavailable. Does anyone know of an o-ring that will work that is available from other sources? Seems crazy to replace a perfectly fine pool light because you can't find an o-ring. thanks for any help.