Pardt,
I appreciate your following through on this forum also. I was about to post here also. This appears to be a true phosphate example and an E/F though as you indicate it is difficult to tell based on the two photos. To my eyes it actually appears to be representative of the early phosphates, both police and army, that came out in early 1944. It appears the barrel is phosphate finished also which I consider characteristic of these early phosphate "prototypes". I use prototype as the theory put forth by Allan and Peter is that this "short run" was used as a demonstration of the phosphate finish for the military and police contracts.
This appears to be a left over of "prototype" phosphate that was brought out for finishing during the later stages of the production and finished as an E/F. Regardless, if the finish can be confirmed, it is indeed a phosphate E/F. [/size] Your research efforts are[/size] are appreciated.....Hopefully, Murton can respond or Jim could perhaps clarify.