In this picture:

The possibly circular thing also looks like a possible air scoop thing
Richard
Thanks for your input Richard ! I have gone ahead with making My underside closer to the WNW version:
WNW:

and the start of My Roden fix:

Still some tweaking to do

RAGIII
PS: It is a Damn shame that the seam on the WNW build appeared back over time

I may have to try to fix that someday!