Blank cassette tapes (IP27)

I have loads of blank cassette tapes most of which have been used once to record an album onto. They are 30 - 40 years old but in excellent condition as have been well looked after. I have recently brought a new CD player that had a tape player on it & I have randomly played a couple of the tapes to see what the recording quality was like and it is not good. However, I put this down to the fact that they were recorded onto from an old stereo system 30 - 40 years ago. Not sure if they are any use to anyone but thought I'd shout before sending loads of plastic to landfill.