Buffalo WHR-HP-GN

Overview
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).

Links of Interest
Buffalo WHR-HP-GN v1 on OpenWrt wiki