two nice guesses, but they are both wrong...
a picture of the face envelope can be found
here, as you said, in origami kit for dummies.
The harlequin envelope is stated as a traditional fold and i found diagrams on
origami resource center.
Here.
i couldnt find anything no my own though, but if you want to fold it again, wouldnt it be possible to partially unfold the model and trying to replicate it through that? it doesnt look too complicated.
i could also try to work out something similar if you posted a backview of the model.