Retrobike will give you some idea of what the frame is worth if you were to sell it, and also an idea of what the components are worth, you might get a surprise. However I would guess it's still rideable. I rescued this 531 frame well over 20 years ago, hand painted black and covered in stickers and filth, and had it renovated, still take it out for the occasional Sunday spin, even though I normally ride a Rose with 11speed Ultegra . . .