Kent: Thank you so much for the suggestion and feedback. I especially like the animated effect switching between before and after.
Your version looks really great. I have been trying to re-create it, but I ran into a couple of problems.
Most basically, I wasn’t able to bake the different parts of the door (those from wood and metal) onto the same UV map. Every time I bake a texture, only the selected object is baked. So I ended up with normal- und cavity maps for all 5 parts of the door (3 metal parts and 2 wood parts). I only uploaded the texture maps of the main wood part of the door for now.
Also, the cavity map of the main wood part of the door is very low contrast. I need to fix that.
The cavity and normal maps of the door knob both had this weird pattern, maybe because I used a too-low poly version of the knob for baking. I also need to redo this part. I removed the texture of the knob for the screenshot.