Delta 46-541
While I haven't worked with this particular lathe, I have restored and sold over 25 lathe in the last few years. I almost always replace the bearings in the headstock and tailstock. It's not expensive to do (although it does take a fair amount of time) and it improves the performance of the lathe, especially an older one like this. While you have the spindle out of the headstock, you can check and replace the belt(s), if needed. You didn't indicate whether this is a 4-speed or variable speed lathe. If it's a 4-speed, you can check and make sure the pulleys are lined up so the belt is vertical and not skewed to one side or the other. If it's a variable speed, the Reeves drive probably needs to be removed, cleaned and reassembled with new grease. Hope these ideas are of some help.
Tim Carter