There was a recent publication on Malta Spitfires by Brian Cauchi. Looking within the pages of that book, there is a colour profile of EP641 and is eqipped with the IFF wires. The main mast is the earlier type with wire attachment points, but no wire. Also no post on the rudder.
There is a b/w photo of this exact aircraft but is difficult to see these details, but another photo of EP691 from the same squadron, confirms this exact arrangement.
regards,
Jack