What a lovely mixte! And big kudos to your husband for jumping on the case so quickly when he saw it on CL!
I'm really pleased to see a little info on "swoopy" mixtes, as there is one near me here in south London (UK) which I've been hoping to find some info on. I've posted 3 photos on Flickr - here's a link to one:
http://www.flickr.com/photos/1093886...n/photostream/
The only sticker/decal is the one at the bottom of the seat tube which just says "OIN" (or "DIN" - sorry, should have got a better pic). No idea what that's meant to signify.
This bike hasn't moved for months but I don't think it's abandoned. I might have to leave a note on it somewhere asking the owner to get in touch...
The only other loop-frame mixte I am aware of is one in San Francisco belonging to 'Meligrosa'. She posts a lot on Flickr and refers to her mixte as "the Frenchie" so it may well be a Peugeot.
Congrats again on yours, ummbnb!