Sgt. George “Screwball” Beurling was the highest-scoring Canadian ace, with 31 credited victories, the majority of which were scored over Malta. BR323 was one of the Spitfires he flew with 249 Squadron at Malta, achieving 5 victories with this aircraft in July 1942. The dual drop tanks on the centerline were a field improvisation, the blue camouflage was applied in theater and has been interpreted in several ways.
Construction posts here: https://inchhighguy.wordpress.com/2021/04/30/airfix-supermarine-spitfire-mark-vc-batch-build-in-1-72-scale-part-i/