I'm actually fine with the large stack of crates - it's mostly going to end up as truck cargo, or as some kind of terrain. I'm also fine with the ammo boxes moulded in rows. I'm less keen on the smaller stack of boxes, as most of the detail is hidden under the tarp. I agree with Ripley that more spare track would be good - you can never have too much of that! And Allied tanks in NW Europe carried a lot of spare tracks.
A few other suggestions:
- I'd suggest that instead of the later British oil cans (the 2 square cans next to the jerrycans) you included more typical British 'flimsies'. See the comparison photo below. This shows a 2 gallon can, a 4 gallon tin (non-returnable), aka 'flimsy', a 4 gallon returnable can (the BEF used these as well as flimsies) and a jerrycan for comparison.
- I'm not sure if it's the photo, but the large US infantry pack (the one with 2 pockets) looks too big. There are also too many of them - they wouldn't normally appear on a tank. Generally speaking, the smaller 'generic' packs are much more useful.
- by the same token, the arrangement of 2 packs under a blanket roll is a bit big, and will be hard to position on most tanks.
- the 2 bags on the right are of pretty marginal value. As is the duffel bag (the one with the strap). Trust me - I've added a lot of stowage to Allied vehicles! What is missing is some bedrolls - these were very common on US and British tanks, and would be much more useful.
- any chance of some spare T-34 track? Preferably in fairly short sections. It's not likely you'll do a Soviet accessory set in a hurry...
- how about a funnel? British crews often carried a large square funnel for refuelling - see the 2nd photo below.
- most importantly, how about a British blanket box? See the 3rd photo below for the types fitted to Shermans.