Siemens Gigaset SX763 2.0

More info and pictures here.

Only firmware version 4.x.x.x.x devices are described here (that is, v2 devices).
 * Per the OpenWrt wiki, v2 devices have part numbers following the S30852-S70x-xxxx pattern

S30852-S709-R331-5 and S30852-S706-R331-5 may be valid Siemens part numbers for this device.

On the DD-WRT forums

Specs
Platform Serial Num. = ? FCC ID = TVU-SX762-SX765, TVU-SX762-SX765-D Industry Canada ID = ? CPU Type = Lantiq XWAY™ DANUBE (PSB 50702 E v1.3) MIPS Rev = ? CPU Speed = 333 MHz Bus = ? Flash Type = ? Flash Chip = Spansion S29GL064A10TFIR4 Flash Size = 8 MB Max Firmware Size = ? RAM Size = 32 MB RAM Chip = Samsung K4H561638H-UCB3 nvram Size = ? ETH chip1 = Lantiq XWAY™ DANUBE (PSB 50702 E V1.3) Switch = Infineon ADM6996I Port-based vlan = ? 802.1q vlan = ? Ethernet Port Count = 4-10/100-LAN Wired Standard = IEEE 802.3/3u Ethernet interface OUI = none specified boot_wait = ? bootloader = ? Flash Card Socket/Type = ? SD/MMC Mod Support = ? Expansion IF types = ? PoE = ? Power = 12 VDC, 1.5 A Connector type/size = ? LEDs/Color = ? Size = ? USB = 1x USB 2.0 Serial Port = Yes JTAG Port = Yes Supported by TJTAG/Version = ? Special Features = ? Radio Wireless Radio = Atheros AR2414 WLAN DSP processor = ? Wireless interface OUI = none specified Antenna Connector Type = U.FL MIMO status = N/A Wireless Standard = IEEE 802.11b/g 802.11g = 6, 9, 12, 18, 24, 36, 48, 54 Mbps 802.11b = 1, 2, 5.5, 11 Mbps WiFi Operating Frequency = 2.4 GHz Radio cor_rev = ? Radio Capabilities = ADSL2+ Other Default IP address = 192.168.1.1 Default login user = admin Default login password = admin Default SSID = ? OEM = ? 3rd Party Firmware Support = ?

Pictures
FCCID TVU-SX762-SX765, TVU-SX762-SX765-D