Here is the raised louvre design for a tropicalised Panzer IV. According to the Squadron/Signal Panzer IV title, these were standard from the late Ausf D onwards, but I don't think that's right as there are photos of Ausf Es with 'flat' engine decks. This seems to be the initial version (I think this is an Ausf F, but it was the same on the Ausf E):
It looks as though the design was subsequently changed, so that both sets of louvres were rectangular and narrower.
Also:
- the Ausf E should have appliqué armour on the superstructure sides on each side of the driver and co-driver. It might be there (I can see some rivets), but the side visors need to be recessed.
- Ausf Ds were retro-fitted with turret stowage bins and appliqué armour plates, just like the Ausf E. I hope this can be done with the kit.