Off the top, I'd say don't touch it! It could be a revival of those fraudulent "phantom parity" stick that were marketed long ago, though I can't imagine Kingston or HP engaging in that fraud.
There is, however, one way these could be ECC after all. If the 4 chips on one end are the main data chips, and the other 4 chips at the other end are of much lower capacity and carry the parity bits. Unfortunately, on the eBay pic, a sticker is covering all 4 chips at one end, so you can't compare.
Oh, there is one other (not uncommon) possibility - some lower capacity chips on the back of the DIMM to carry the parity bits. Do we have a pic of the back anywhere?