Liam Wyatt wrote:
So, I ask that when we copy images from galleries/museums/libraries, or even when we take photos of the originals ourselves, we include the comprehensive attribution
I agree that this is a good idea, but for another reason: We're trying to provide free *knowledge* and this includes knowing who the artist was, even if copyright law doesn't require attribution.
Whether such attribution is legally required or not, is a test of whether your country's legislation follows the Anglo-American "copyright" doctrine or the continental European "authors rights" doctrine. The difference is the so-called "moral right", that grants the author a right (of little commercial value, but supposedly of moral importance) to be attributed and respected, even after the copyright expires. But for us, our mission to provide good knowledge should cover more ground than any such legal requirement.
I have another example. The article about Swedish 18th century arch bishop Haquin Spegel contains a portrait, stored at Wikimedia Commons. There, the description says "author: user:Narym", which is highly misleading. Narym was the user who uploaded this image to the Swedish Wikipedia in September 2004, and when all images were moved over to Wikimedia Commons in July 2006, the name in the version history (uploader) was used to fill in the author field of the Information template. The CommonsHelper bot (written by Magnus Manske, operated by user:Nicke L) added that the image was "originally" from the Swedish Wikipedia, which is also incorrect.
So, what is the crime here? What's bad? It's bad that we, as a free knowledge project, don't provide more knowledge about the real artist or background of the image. Even though Swedish law (to which both Narym and Nicke L are subjects) requires attribution, this is a very weak requirement and we're not facing any legal threats.
The illustration in question (File:Haquin Spegel.jpg) is a woodcut published in a magazine in 1873. Woodcuts are always based on paintings, but I have no information about which painting was used here. The woodcut is signed Evald Hansen, and I just wrote an article about this Danish-Swedish xylographer. The entire magazine is in the public domain, and several complete years have been scanned. Many of the illustrations have been uploaded and Commons even has a template:PD-SFJ for images from this magazine.
Next thing, I will improve the image description and link it to the xylographer. But this is because I want to improve the free knowledge about the artist. I'm not pushed by legal requirements.
In fact, the Australian National Gallery and similar institutions are more helped by Wikipedia's free knowledge about artists than hurt by our occasional failure to properly provide attribution.