Down to the last of my mystery wrapper. From the aroma, flavor, and rich dark chocolate color, I reckon it to be some Mata which I scored way years ago. Here's a pic with light shining thru, so you can see the thinness of it:
Here's a pic trying to show the color... my phone cam does not want to capture the dark choco...
and here it is applied:
and it's a crying shame there's no way to convey the velvety feel of it.