Identify revision of Arduino Ethernet shield

I have an official Arduino Ethernet shield which has no revision number marked on it. I know it's not a R3 shield, since it looks different (although superficially similar) to the picture at http://www.arduino.cc/en/Main/ArduinoEthernetShield.

My shield looks like this:

I'd like to know the shield revision so I can find the appropriate schematic.

If they're not going to be diligent enough to put revision numbers on the silk-screen, what we really need is a visual catalogue of these shields!

Looks like a R2 board. It has a 6 pin ICSP header on the bottom?

Yes. It does have the female ICSP header under the board. However, I've since discovered another picture on the Arduino website which claims to be an Arduino "V3" board

which looks identical to mine. I'm not sure whether V3 is the same as R3 through.

That pic is not an R3. The R3 has two additional header pins on both the power header and J1. Yours doesn't have those.
Take a look at the pics here:

The top pic is the R3. The bottom smaller pic is the R2.

Edit: I use "R2" as the revision number, even tho that may not be the official designation for that model. I used that only because it was the newest board prior to R3.

Solution!

By comparing the Eagle CAD schematic and PCB layout files posted on the Arduino website I've determined that my shield is in fact a V6 shield. The V6 has four LEDs adjacent to the crystal and the logo, and the two capacitors along the bottom edge of the board.

I don't know how, or indeed if, the R# designation correlates with the V# designation, but since my original goal was to find the appropriate schematic for this board, I have now succeeded.

I got sufficiently frustrated by this whole experience that I decided to make exactly the visual catalogue of Arduino Ethernet Shields I've been craving.

Behold the Atlas of Arduino Ethernet Shields: http://www.smallshire.org.uk/sufficientlysmall/2012/01/01/an-atlas-of-arduino-ethernet-shields/

@robsmallshire: Well done!

I am kinda surprised that the Arduino website hardware section does not have an archive of EOL products. Maybe they might consider that, now that they have a good example to use as a template!