This is partial answer just addressing the first part of your question.
I am aware that the prophets may not be depicted in art work
This is the mainstream tradition of Islam; there is no direct Surat in the Qu'ran that supports this - that is mentions both image and prophet; however there is one that solely mentions image:
And the people of Moses made after [his departure] from their ornaments a calf - an image having a lowing sound. Did they not see that it could not speak to them or guide them to a way? They took it [for worship] and they were wrong-doers
- 138 The Heights (Al-A'raf)
When an image is taken for worship is called an idol; and just before this ayat we have also:
We took the Children of Israel across the sea, but when they came upon a people who worshipped idols, they said "Moses, make a god for us like theirs". He said, "You really are a foolish people: [the cult] these people practise is doomed to destruction, and what they have been doing is useless".
7.138-139 The Heights (Al-A'raf)
There is however a direct reference to prophets and image in the Hadith.
When Allahs Apostle arrived in Mecca, he refused to enter the Ka'ba while there were idols in it. So he ordered them to be taken out. Theo pictures of the (Prophets) Abraham and Ishmael, holding arrows of divination in their hands, were carried out. The Prophet said "May Allah ruin them (ie the Infidels) for they knew very well that they (ie Abraham and Ishmael) never drew lots by these (divination arrows) . Then the Prophet entered the Ka'ba and said "Allahu Akbar" in all its directions and came out and not offer any prayers therein".
Bukhari 5.584
What's surprising here is that the Prophet says nothing about the images of the prophets themselves, but what they were made out to be doing in the image - divination - and this aligns with another injunction in the Qu'ran:
You who believe, intoxicants and gambling, idolatrous practises and [divining with] arrows are repugnant acts - Satans doings - shun them so you may prosper.
5.90 The Feast
And again here we have the injunction on idolatrous practise.
The question that needs asking is whether whenever an image is made should it be taken that it must be for idolatry; and if not, then by what do we distinguish?