One funding organization recently contacted me about the possibility about funding an open access "Wikipedian in Residence" at an OA organization, in order to pursue projects like this (which is pretty straightforward for anyone with lightweight technical knowledge and dedicated focus). I'll ping them about that idea to see if it's likely to happen.
(Similar but related are open educational resources -- CNX.org textbooks, Pratham Books, etc. -- lots of really good appropriately licensed illustrations there.)