Edited to clarify correct files - Sorry!!
As luck would have it as I post for help I find a solution!
This is how I solved it:
1. Connected an ASIX USB NIC and configured it as GREEN
2. Connected a Conexant USB ADSL Modem
3. Connect to the Endian and enable SSH
4. Connect via WinSCP
5. Edit /etc/modprobe.conf and add the following line at the end: install tg3 /sbin/modprobe broadcom; /sbin/modprobe --ignore-install tg3
6. Save
7. Edit /etc/modprobe.d/modprobe.conf.dist and add the following lines at the end: install tg3 /sbin/modprobe broadcom; /sbin/modprobe --ignore-install tg3;
install skfp /sbin/modprobe marvell; /sbin/modprobe --ignore-install skfp. Note that these are two seperate lines!
8. Save
9. Reboot
10. Go into the "Network Configuration" menu on the dashboard and the NICs will be available to configure as you wish.
11. Remove the USB NIC if you wish.
I have tried this and it works, the cards I have are listed as follows in the lspci output:
01:00.0 Ethernet controller: Broadcom Corporation NetLink BCM57788 Gigabit Ethernet PCIe (rev 01)
lspci -n show it as the following:
01:00.0 0200: 14e4:1691 (rev 01)
If it stops or gives trouble, I will update.
I do not know if these changes will survive and update from Endian, but seeing as they are very few and far between, I suspect it will not be a problem. If they do update the kernel at some point, these hacks should not be necessary and the NICs work fine with newer kernel distros.
I hope someone finds this helpful!