Steven et al,
Please correct me if I am wrong ( you will get extra credit
) but why in the world are we talking about this?????
Take your own reference photos.
Get releases or don't.
No reason to push the envelope, seriously! It's OK or not OK.
Respect your clients, and talk to them.
Get a copyright release from a photographer, or don't use the photo.
I don't really understand why it's necessary to dance on the edge unless you like that kind of thing.