Installed firmware-rtl_nic.tcz & rebooted...
onboot.lst
/mnt/sda9/tce> cat onboot.lst
firmware-rtl_nic.tcz
firmware-ralinkwifi.tcz
wifi.tcz
rfkill.tcz
jwm-full.tcz
Xorg-7.7.tcz
rxvt.tcz
wbar.tcz
xf86-input-synaptics.tcz
firefox-ESR.tcz
dmesg :
r8169 0000:04:00.0: Direct firmware load for rtl_nic/rtl8106e-1.fw failed with error -2
r8169 0000:04:00.0: Falling back to sysfs fallback for: rtl_nic/rtl8106e-1.fw
Generic PHY r8169-400:00: attached PHY driver [Generic PHY] (mii_bus:phy_addr=r8169-400:00, irq=IGNORE)
r8169 0000:04:00.0 eth0: Link is Down
r8169 0000:04:00.0 eth0: Link is Up - 100Mbps/Full - flow control rx/tx
2 ERROR lines related to rtl_nic persists. 'unable to load firmware' error has disappeared.
Wired Ethernet did work even without including the firmware - RTL_NIC
dmesg.tinycore - attachment included.