With its body and the slide assembly made from bronze, the origin of this cross-slide-mounted indexing unit is unknown - though clearly intended for indexing on a small plain turning lathe, or possibly on a special-purpose machine in a watch or clock-making factory.
Although fitted with a Lorch collet (and Lorch did make a dividing unit), the fitting of the slide to the bed of the lathe is not Lorch-like, nor are the hand-stamped numbers and letters. Equipped with the usual 60-tooth gear (to provide the greatest number of factors while maintaining compact dimensions), the unit is inscribed on the outer section of its cylinder with all the possible divisions.
Almost certainly intended for helping with the manufacture of small gears, the writer believes from its appearance that it would have been made circa 1880 to 1900. A search through contemporary literature has not revealed anything of a similar construction, so if you can provide more information, the writer would be pleased to hear from you.