Hi there,
Interesting (and good) question in my opinion. My initial interest in the DV 376204 and 376205 some months ago (the cousin Perpetual Calendar series, though quite a different movement) had lead me to ask the same question as you, to the extent that I started listing and preparing what I will reveal below.
The Da Vinci line is not discussed as much as the other lines (say Pilot, Mark, Portuguese, Big Pilot, Aquatimer …) but no less loved I am sure. I love the line myself but have yet to pull the trigger on one though the 376601 is within my sights.
My understanding is that the 3764s are all circa 2007 and later, and all have the same 89360 movement, but a key change was in the dial: early ones had flat plain dial. Later, there was an unannounced change to dials with the engraved wavy stripes, as enlightened by our moderator Michael in this discussion. You can also see in the pics the differences between the wavy textured striped dial, and those with the plain flat dial.
To answer your question 376403 has a plain flat dial, while in 376413 & 376421 are the wavy textured striped dials. The former 376403 is discontinued I believe, but if you search hard enough I think you will find dealers with unsold ones.
As to the differences between: 02 and 11; 05 and 09; 06 and 12; 13 and 21; 14 and 22, I too would very much like to know. The old and new references appear to have the same pics in my trawl through the catalogs and web, but it could be because (lazy?) dealers or re-sellers reused the older pics, but I doubt this can be a definitive reason.
For convenience, here is my attempt to have a complete listing of the 3764XX…if anyone can give corrections/clarifications, please feel free to do so:
01 white gold, ardoise dial, strap, flat dial
02 rose gold, silver-plated dial, strap, flat dial
03 Stainless Steel, black dial, strap, flat dial
04 Stainless Steel, blue dial, Laureus Limited Edition, flat dial
05 Platinum, silver-plated dial, strap, flat dial
06 rose gold, silver-plated dial, bracelet, flat dial
07 Stainless Steel, black dial, bracelet, flat dial
08 nil
09 Platinum, silver-plated dial, strap, flat dial
10 white gold, ardoise dial, strap, wavy/textured striped dial
11 rose gold, silver-plated dial, strap, flat dial
12 rose gold, silver-plated dial, bracelet, flat dial
13 Stainless Steel, black dial, strap, wavy textured striped dial
14 Stainless Steel, black dial, bracelet, wavy textured striped dial
16 Platinum, silver-plated dial, active collection, strap, wavy textured striped dial
17 white gold, ardoise dial, active collection, strap, wavy textured striped dial
18 rose gold, silver-plated dial, active collection, strap, wavy textured striped dial
21 Stainless Steel, black dial, active collection, strap, wavy textured striped dial
22 Stainless Steel, black dial, active collection, bracelet, wavy textured striped dial
…. And there is a further Collectors Forum Da Vinci ‘CFDV’which is also based on the 3764 I believe, although I have not come across the reference number. You can find out more in this discussion and article.
*from IWC Workbook Search, an application created by Stefan Weeber.
