Italeri fast build Shermans WIP

I picked up these 1/72 Italeri M4A3 75mm Sherman tanks the other day on sale at a local model shop, I wanted to use them to support some British infantry. A bit of quick research on the net revealed that the British had not deployed these in NWE in '44. I therefore posted on TMP to see if my fellow TMPers had any ideas for adapting them for British use. Now, I am not ultra obsessive about getting the details just right when it comes to AFVs (I have no problem with those who are), but I did want it to look vaguely right. One of the suggestions was that this tank could probably stand in for a Sherman III, and would be helped by the addition of a "blanket box" on the rear of the turret. With this in mind I made a box out of balsa and plastic card and added an aerial (or should that be antenna?). It has had a quick undercoat brushed on of Derivan Mattisse Pale Grey primer.  I'm open to suggestions as to how I can make it look more"British".
Ideally these tanks are intended to support 43rd Wessex Division sometime in '44. Not sure what markings they will need yet, I have the allied star decals that came with the kit and guess they might come in handy.