The machine's nameplate was originally affixed to the rear of the bed. The serial number should be stamped into the top right end of the front way. To ID the machine, you need to post one or a few photos of it. If it has individual gear guards, it is not necessary to remove them. If it has a wider belt and gear cover, one or two of the photos should be taken with it opened. At least one photo should be taken from a point about 2' up and 2' away from the machine, measured from the bottom front edge of the left leg. One should show the largest change gear, which will usually be found installed on the left end of the lathe. And one should show the motor switch and the change gear guard.
I corrected (will correct) the Craftsman model number that you were asking about to one that at least has the correct number of digits in the correct order.