Thank you all for your help.
I was able to contact a curator in Belgrades aviation museum and he povided me with some close shots.
Mr. Korellis confirmed that this was an extent field modification, and during his research for his book, he contacted all major air museums in europe and US, but no...
1943 and after in Meadle East, Sicily - Italy and finaly Greece. Mr. John Korellis told me that all Mk.Vc and Mk.IX in midle east and Italy used those racks initially before the later ones introduced.