You may have figured out the link yourself but in case you didn’t here it is.
This was a case where the similarity of design plus the remnant of the double helix EE mark but most telling the appearance of the Z tally mark betrayed the Eaton underneath the CI overstamp
Both items were advertised as “butter knives” on ebay, the first in 2004 and the second a decade later. Identical in length and similar in weight to dessert forks, If I can souce more I will buy them and call it a set of 12 fish knives with forks preferably without the overstamp although that does seem to make them more. desirable – or to use the auctioneer’s quaint term “important”.