@ungutknut: I think that the Fairphone logo is bound by this:
All Web Content of the Website is licensed under Creative Commons License Attribution- Non Commercial 4.0 International (CC-BY-NC.SA 4.0), unless stated otherwise. For more information on the license, please visit CC BY-NC 4.0 Deed | Attribution-NonCommercial 4.0 International | Creative Commons.
Your appearence on Thingieverse is not commercial (unlike Shapeways), is that correct? In this case there shouldn’t be a problem to use the Fairphone logo.
You could of course always use the old logo, or the avatar:
https://forum.fairphone.com/user_avatar/forum.fairphone.com/vervoon/240/8095_1.png
