I have a Cushman 3 jaw, 9 inch chuck, on my Sheldon lathe that the jaws are non-reversable . The only Numbers I see on it are 8B4903. How does one go about getting a set of jaws? The ones I have are such that when trying to turn close to the chuck one risks crashing into it with the post or the compound. Is it a better solution to just shop for another 3 jaw?