Franken With Style - 6139
This 6139 is not something that Seiko originally brought out, it is in fact a piece that being put together with parts from different variants of the 6139 series. People usually call this kind of watches Frankenstein watch, or in this case a FrankenSeiko.
With a good running 6139 inside, it has a 7100 Vader dial and hands, an early 6010 case, a Chinese Kanji day wheel, and lastly a caseback from a relatively less seen 7011. Really one of a kind. Although the watch right here has parts from 'at least' 4 different watches, they all do work together without any need of modification or alteration. They are all from the 6139 series, and most of the time original parts can be shared among them. This 6139 is a very good example.
Fake parts are not acceptable. But if one was built with genuine parts to form a Frankenstein, and if you do it right, it could be a very nice 'one of a kind' model. Just do it right.