Using your formula center of spindle to bed is about 6in X 2 so 12 inches . Bed length is about 51 and a quarter inches . Attached to a leg is a tag 5 stud then graphs for spindle screw thread , cast into the legs WF & I Barnes & Co , Rockford ILL USA and a number 5 . The 5 appears at the top WF & I Barnes Co toward the center and Rockford Ill at the bottom. Note the I maybe a J . On the Apron is 2 Patents the first Pat Sept 21 1880 second is Feb 15 1887.
I can not get my photos to print on this thread but can put some on my phone and maybe send them to you . Thank you for your efforts hope they help to find a home for this old lathe or the parts to repair it
Jeff