Auf Englisch getippt, weil dies ein Thread von mir auf einem anderen Forum ist, und ich nicht das ganze übersetzten möchte:
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The Rolex Submariner Date, ref. 168000 is a very interesting model since it was made for only about 9 months.
The Submariner Date 168000 was introduced in the middle of the R-series around mid 1988. The successor, the Submariner Date 16610, was introduced a few months into 1989.
What makes the Submariner Date 168000 special is the fact that it was this very model reference that introduced the use of steel 904L instead of the steel 316L that was used before. Furthermore, the 168000 neither had its reference number stamped on the certificate nor did it have it stamped on the inner side of the caseback. Both would say "16800". It has been said that the extra "0" was added by Rolex for INTERNAL use only in order to keep track on which cases were made of steel 904L and which were made of steel 316L. In that respect, the reference 168000 never was an "official" model.
Most 168000's would be seen with a glossy dial with white gold surrounds; a dial which - like the 16800 which also had glossy dial variants - could develop the socalled "spider web" effect due to a fault in the paint mixture used back then, causing small spider web looking cracks in the surface of the dial. Naturally, the matte dials did not have that issue.
It seems, however, that very few examples of the ref. 168000 did exist with a MATTE dial, too, but I would like to have this put up for discussion if you think NO 168000 with a matte dial existed.
Let's have a look at these pics from a listing on a Danish site (got the permission from the seller to post the pics here). What do you think? It this a Submariner Date ref. 168000 with a matte dial installed at the factory or is it a 168000 with a matte dial from a 16800 installed later? 
(Bilder von einer dänischen Vintage Rolex Seite).
