This is from chip guide.
If the eBay seller got that much for them, they are probably real. Dunes used HHR in the mid 70's and into the 80's.
I have often wondered if CPC would do replicas, maybe someone could shed some light on this. I understand not wanting to make chips that could be used as forgeries to collectors, but if there were some differences from the originals to make it known to collectors they were copies? Would it be a copyright thing?