no, it was more a technical question: the sky is fine as is
however, to add a better rolling of pattern let me suggest this:
you may need to import on photoshop or another advanced paint program your sky texture, apply a "rectangular to polar filter" (photoshop: distort/polar coordinates)
so to have the picture wrapped as a circle, fix the junction...
then bring back to normal the image with the reverse "polar to rectangular" filter;
this unless is gloom engine itself to mess up the edges... :/
of course, if you want to stay all-amiga you can either use an old PS in shapeshifter, else i have no idea whether ArtEffect had this filter...