Catch 22 really. 'Lessons Learnt', if not acted upon, can soon turn into 'Top Tips for the Enemy', therefore for both security and embarrassment reasons not much filters out.
Tie that in with the Treasury and it becomes a case of not much needs to filter out because, hey, we won and our boys made do with the kit they had. Spend the cash on asylum seekers.
Much safer (?) and cheaper to stay pals with the Americans and borrow their stuff, particularly when they're out on a diplomatic limb, as they're more likely to want to be pals too.
Shop floor-wise, just pray you get sent somewhere with a US element and you should be able to wangle uniform items and food.