Clearly I am mistaken, then, about the correct ribbon - as illustrated on the award document. I was popping back and forth between several on-line sites and trying to sort out the earlier award from the later version and 'merit' from 'Civl Merit'
However, it still looks to me as if the owner or his tailor used a substitute, a common enough practice with rare foreign awards, I'm afraid.
I'm not sure how one would go about tracking down the owner, other than trolling the London Gazette or whatever the Chilean equivalent would be, if such exists, and I'm not familiar enough with the Gazette to guess whether or not such an award would appear there. Frustrating!