I sorted my pile of drill chucks today, and one of them was a Jacobs #16 ball bearing super chuck. It seems to be in OK shape, except that, sadly, its "rear end" is tapered for some sort of small taper, and is quite torn. I feel like, if I had a proper tool or technique, such as a proper reamer, I could ream the hole for a bigger Jacobs taper and get a functional chuck.
So, is there some simple procedure for fixing said chucks? It would be sad to throw it away.