Hi Simon,
I think the spray deflector on the late war VIICs was the same as the deflector on the early VIICs. If you are looking to draw one I would recommend looking at early war photos because there are plenty of shots showing this feature in good detail.
One thing not to forget is that the majority (perhaps all?) of VIICs at the end of the war had armoured plate above the spray deflector (but not below the deflector). This plate can make it seem like the spray deflector did not extend as far out as on the early VIICs. However, if the armoured plate was taken away then I'm pretty sure the dflector would look exactly the same as earlier boats.
Cheers,
Dougie