"Supports AP, AP client, AP bridge, WDS, and universal repeater modes"
"1244-00000737-50Z" is silkscreened on the board in the FCC photos.
The FCC test report lists the following as identical models
The serial port is under the PoE injector board.
[ TX GND RX ][ VCC ]
FCC documents show two USB ports installed, but the shipping model does not appear to have them.
There are solder pads for seven USB ports. Solder pads for two triple stacked USB ports are located on the front of the board, right next to the leds. A single usb solder pad is located beside the power socket, this location is obstructed by the antenna fitting.
Linux GPL sources are available at http://www.edimax.com/images/Image/OpenSourceCode/Wireless/Router/BR-6475nD/Edimax_RT3662_6X75nD_GPL_20110920.zip
Build environment is Fedora 7 i386.