Bucherer Automatic Chronograph Lemania LWO 283 (ETA 2892 plus DD module), late 1980s

The Bucherer reference number 283.500
does not reveal the make of the movement inside. Wrong! This reference number is a proof that there is a Lemania LWO 283 at work here. Bucherer's model numbers often include the number of the watch movement used.

obsidian (Dan) posted this interesting fact on the PMWF.com:

Wow, I think what you have there is a rare Lemania LWO 283 movement!

It was the only movement marketed by Lemania that it did not design. They hired Dubois Depraz to design and build a module that would fit on top of an ETA 2892 and give the same functionality and a similar (but not exactly the same) layout as a Valjoux 7750. Later, they sold the rights to the module back to Dubois Depraz which used it as the basis for future chrono module designs. One of the odd distinguishing features of the LWO 283 was that the movement came with the date magnifier already mounted over the date aperture-- it was an integral part of the movement.