Excellent news. Apparently the painting contacts are better than the photography ones. And yes that age makes sense with the spellwork starting to fail and the subject. I expect between us we can probably date it to within twenty years, more likely closer to five in either direction. But we have the history of magical art training to a whole other level thanks to how apprenticeships work. Looking I'd guess closer to three centuries than two, but I'm not the most experienced around here.
We artists are a weird bunch. Some things stay consistent for centuries, other things change very couple of decades or depending on the mood or skill of the artist. I don't think anyone should be doing this without waterproof boots and clothes they don't mind covering in water and/or paint (sometimes the whole thing can break down and the result isn't pretty).
Braith says it will probably take a week or so for her friend to be set to travel, if you have somewhere safe to store it until then we'd be grateful.