If it's not too late he really needs to change those side bins to the production variant. The ones he has used are for a Mk1 or Mk2. Some VERY early Mk3's had them (or more likely MK2's upgraded to Mk3 standard) but crews had difficulty opening them when Mk3 turret was fitted so they changed to the side opening variant. Same goes for the large round hatch on the back of the turret, this is a Mk2 feature to enable the 17 pounder to be removed but wasn't needed for the 20 pounder so was deleted on Mk3 production (or welded shut if a Mk2 turret was upgraded to Mk3 configuration). I think Andrew may have based his model on the Tamiya 1/25th scale kit, which was based on the Bovington "cut in half" Mk3, which was originally manufactured as a Mk2, upgraded to M5, then backdated to a Mk3 when it was turned into a display, which is why it has a mix of earlier features. That being said, many British Mk3's where upgraded all the way to Mk12 so you could see these early features (top opening bins, hatch in turret rear, angled loaders hatch) on a British later mark, but it would be very rare and very unlikely on a NATO tank.