I think kof2003 encrypted pcb c roms have almost the same protection as svcchaos c roms:
mvs xor + bitswap
lol there's an easy way to verify:
take the kof2003a C roms, join c1c+c3c, and bitswap it (hexworshop can do that) and see if you get a matching crc for c1
I doubt it tho, svc protection isn't as easy as you think (mvs xor + bitswap)