filling the moon air-intake

[COXBOW]

Hi Folks,

I would like to know how you’ve filled the moon air-intake behind the rear side window (for those who still had to do it!)
By welding an iron plate? Filling it with tin?

Doe you still see the shape of the original moon (like the older 1200 that didn’t have them) or is it flat and smooth?
If so what are the steps to do it?

Thanks

Serge