A rare 1999 platinum Rolex Daytona, a one-of-a-kind private commission, could fetch $1.7 million at Sotheby’s as luxury watch ...

The watch is part of a single order of four custom Rolex watches created between 1998 ... 16516 to appear on the block also had a mother-of-pearl dial, but in a rainbow hue with Arabic numerals ...

It was privately commissioned, custom-made for a client — something almost unheard of for Rolex. "It's very unusual ... each with a different dial. The watch heading to the auction block is ...