the self-portrait by Károly Csomafáy is very interesting. It's fascinating to think about how the artist saw himself, and how he chose to represent himself in the painting. The texture and colors are also very beautiful.
it's an interesting question to think about what you would do if you bought an old painting that you didn't like the frame of. Personally, I would probably try to find a way to change the frame without damaging the painting. I think it's important to be able to enjoy the painting as much as possible, and a frame that you don't like can really detract from the experience.
Changing the frame does not damage the painting if it's done by someone who knows how it's done. You're right, I would change the frame too as the painting is important not the frame, but the frame is there to add some value, so might as well be a nice one I like and think it's going to make the painting loom better.