Around 3.5-inch centre height, and 20 inches between centres, the U.N.D. was a precision bench lathe* distinguished by a diving attachment built into the front face of its plain-bearing headstock. The only know survivor, illustrated below, has been fitted with a Goodell-Pratt compound slide and, by the appearance of the many its many home-made accessories, has had a hard and productive life. Unusually for a lathe of the late 19th and early 20th century, the 3-step headstock pulley is overhung - and may have originally contained an epicyclic reduction gear to obtain low speeds
Unfortunately, with an absence of sales literature, it is impossible to tell anything of the maker's background, country of mske or even how original the machine is. However, it is likely that the lathe was built in America between 1890 and 1930 with the headstock coming from the manufacture's range of optional extras. If you have a UND lathe the writer would be interested to hear from you.

See the various articles on American Precision Bench Lathe manufactures: B.C.Ames, Hjorth, Potter  Pratt & Whitney, , Rivett, Stark, Wade, Waltham Machine Works, Wade,  Pratt & Whitney, Rivett, Cataract, Hardinge, Elgin,, Remington, Sloan & Chace, etc.