We should test that changing them replaces them one to one and doesn't reset the ones we've placed i.e. turning shields into arbitrary 1*1 paintings.
I'm happy to give some of the smaller motifs a go but again I don't have time to do much of the research. So if y'all could compile a list of 'westeros-historic' events or people that would be cast on canvas that would speed this up significantly. Or tapestry for that matter.. are paintings actually canon?
It's odd, I can't seem to recall nor find (on search of ice and fire) any mention of 'paintings' although a ton of other objects are clearly painted or dyed: tents, the canvas of sails, vests, shields, thread of myrrish carpets, boats, wood, statues, you name it. But never is there explicit mention of something along the lines of "Ned admired the dusty painting of Winterfell".
Portraits are mentioned but the context is ambiguous as to whether they are 'woven' or really painted canvas. There is one clear mention of an explicitly woven portrait in Jamie IV - A feast for crows, but the other mentions are either world of ice and fire, portrait in a more figurative sense, and that one nefarious chapter of Winds of winter: Arrianne I. /shrug
Edit: Oh and when you do give suggestions, please compile some canon details or at least give references.. I don't wanna have to research what or how a certain event was described...(again it just encroaches on the precious 2h of the week that I can spend on this)