Looks like I have more research to do but from what this website says mine do look a lot like the un-genuine pictures.
I'll obviously only now be offering to pay via Bitcoin and not these bars until I get things straightened out.
I believe there is trusted escrow on this forum who can test your bars.
I've already messaged mj to handle escrow as I've used him before for handling physical escrow deals. He said he can't test precious metals but knows a trusted escrow that could for me to use, but now obviously I have bigger fish to fry than trying to buy a Cas coin. Going to get this straightened out first with the man I bought them from. Until then obviously I can't offer these for payment, but I still doubt they're fake.