If you buy a sticker off fleabay just make sure it's the latest one. There's often some of the old ones for sale which is as good as not having one at all!
Only really matters for cosmetics unless you're needing to get ti past an ACU scrutineer, but jobr's solution is the best way to go in the absence of a freindly dealer.
Another route might be to pop into an Arai truck at a race meet and get them to check your lid on the spot and affix said sticker.