Since replacing the babbitt bearings is a difficult path to pursue, it is my inclination to leave the existing wear pattern in place. I don't know of any way to renew that bearing surface to include both the babbitt side and the spindle side. If you are lucky, you still have a clearance shim or two under each cap. If you're out of shims, and your spindle deflects, then you are looking at making an oversized spindle or doing a sleeve or buildup job on the spindle you have. Whatever you do, consider your options carefully, this is the "heart" of your lathe.