Volfy, You can have a perfectly level bench but you still need to level the lathe to the bench. Left to right and front to back and shim as needed. Also check that the tailstock is true or you will turn a taper and not know it. Easy way is to turn a test bar between centers. Turn a bar and leave a collar each end of equal size. Now go to one end and take a very light cut. Leave the dials and settings alone and move the saddle to the other collar and take the same light cut. Now mic the collars. If they are the same size you are running true and your tailstock is perfect. If not you need to adjust the tailstock one way or the other to compensate for the taper and take another light cut. Keep doing this until you are true or so close you can't adjust it anymore. You won't be turning between centers for a hub but when you drill a hole to thread your hub it will be off and your hub and prop won't run true. Hope this might help. Once you set up your machine you will be fine and your work will improve too. All you need to do is check it once in a while unless you move something. Then you need to do these things again. Actually the BP isn't all that big for its 2100 pounds just very rigid. Amazing that the thing is 50 years old and way better of a machine than some of the imports ever could be. Most copied machine I know of.

Tim