I've found that old film sometimes has a lot of "spring" from being wound up for decades. Sometimes so much it's hard to put on the reel. I've found that unreeling the film (in the dark, of course) and putting it in a developing tank (without reel) for a few hours can help the film "relax" so it's easier to roll onto the reel. I've also had old film break when trying to unreel it - but it was probably hopeless anyway. Good luck.