Denoise?

[denzjos]

On your post I see an error on the fourier plugin and you use gimp 2.8. I've used gimp 2.10.32 and the photo on my post is reasonable nice because i'ts smaller than the original. I've tried several Gmic-Qt plugins but I found not one to do the job, so I haven't use it on this image. The image with the original dimensions, jpeg quality 94% : 
   

---

You can try this : https://vanceai.com/old-photo-restoration/