So in order to build my reference machine I started from here https://thepcspy.com/read/building-a-kiosk-computer-ubuntu-1404-chrome/ and it uses Ubuntu Server 14.04.5 and because of hardware limitations, 32 bit edition. Apart from having to substitute Chromium for Chrome, the reference machine, with a few tweaks, such as ofris to freeze the user's home drive and some OpenBox customisation to remove the right click menu, etc, it does what I want to; producing a pseudo-Chromebox, but with better hardware compatibility than ChromiumOS.
Now when I came to clone it, that was a bit more difficult, and after playing with a few cloning solutions, Gparted Live CD has been the most straightforward, as there are only going to be at most 12 clones.
The problem is that on the clone computer, the network adapter instead of being eth0 is named eth1 and in /etc/network/interfaces the commands are auto eth0 and iface eth0 and because for some reason Ubuntu has labelled the card eth1 (as the output for lshw shows) and there is no eth0 in the system, the network comes up as disabled to begin with (again from lshw).
Duplicating the commands for eth0 in the interfaces file quickly got the clone running but I still don't understand why the card is being labelled eth1 in the clone instead of eth0 and I don't want to have to work with the possibility other clones will have some other random number assigned to their sole NIC. The two computers are in every way identical except, of course, for MAC address, and I just don't understand how Ubuntu has decided on the original the card will be eth0 and on the clone it will be eth1 when the clone has no other ethernet card in it.