Buffalo WHR-HP-GN

Manual

The device is presumed to be manufactured by Cameo.

Review of the device on it186.com (decent photos)
 * This device appears to be using the same board (and 2T2R capable WiFi IC [AR9283]) as the Buffalo WHR-HP-G300N.. despite being a single-stream (and single antenna) device.

On the DD-WRT forums (internal shot) Buffalo WHR-HP-GN / WHR-HP-G300N on the OpenWrt Forums
 * Serial settings are 115200, 8, N, 1

Default login credentials and the IP is per Buffalo's manual.

The default SSID for the device appears to be the MAC address (no delimiters, upper case hex letters).