Remove a honeycomb pattern from an image using GIMP

I have a 1925 wedding photo that has a background honeycomb pattern that I can’t seem to remove.

I use GIMP 2.10.32
I’d like to use an FFT filter but can’t find one in GIMP.

There use to be an FFT filter under ‘spectral filter’ about 10 years ago but it isn’t there anymore.

I need an FFT filter for this photo.

One other thing - I can’t seem to remove the ‘hazy’ white stuff clouding up this photo - HELP!

Thanks

First Download G’MIC other there https://gmic.eu/

Once installed, open GIMP or restart it, then go to Filters > G'MIC (or G’MIC_Qt), a window opens, go to Frequencies > Fourier Transform

Then in GIMP, paint black on the white stars on the [Magnitude] layer (not in the middle and do a better job than me, I did forgot a lot),

Once it’s done, just go to Filters > G'MIC > Frequencies > Fourier Transform while the [Magnitude] layer is selected and in G’MIC as input layers put active and below (it will auto-invert), then just click OK

Duplicate your image, put the one on top in Multiply Mode, then right click on that duplicated layer in the layer stack > New from Visible.
Un-tick visibility from the layer in the middle now, and put the one on top in HSL Color

Again create a New from Visible by right-clicking on the top layer, you should have a lot of blue on your image

On that last image/layer, just go to Colors > Desaturate > Desaturate, Mode Luminance or Luma will get rid off the blue and remove that “hazy white stuff clouding”

Comparison: this method do not affect the people on the picture, no adding contrast nor changing luminosity (if so, it’s so negligible)