As part of my trouble shooting it looked like the Kernel/Basic ROM was shot so I thought I'd have a go at burning one. Turns out it's actually pretty easy with the right equipment (It also turned out the Kernel ROM on the board was fine after all).
I bought myself a "TL866 II plus" and some 27128 EPROMS from Ebay.
This site has the C64 ROM images and which EPROMS are compatible:
https://ist.uwaterloo.ca/~schepers/roms.html
The UV Erasable ROMs I got were actually ST27c128 which the software didn't have an entry for, but I read on the internet that if you just use the AMD AM27C128 and turn off the "Check ID" it works fine, and it does.
Read part 2 ==>