I think solder before paint might be the better option. In my experience, the edge to edge nature of the joins makes it difficult to do neatly, so needing an element of fibreglass brush work to tidy up afterwards. Trying to avoid damaging an already applied paint job would make that job even harder. But.... from the evidence above, your soldering is very tidy so maybe it's not a problem. Good luck with it, whatever order you decide on.