Spotted: Rolex Datejust 16013 with Cummings logo dial.
In years long past, Rolex used to make quite a few company dials.. Commemorative pieces, often printed in the US. In fact, I have a folder of this practice around here somewhere – will look it up.
The above Datejust was awarded for a 25-year anniversary to one of Cummings (engine builders) employees and comes with provenance. Cool piece.
Check it out at our friends of Amsterdam Watch Company: http://awco.nl/index.php?taal=1&id=3189&spec=2