The green 0-407- coded wrappers that were first used for the 9th series were also used for the 11th series. At first, the same exact wrappers from the 9th series were used. Sometime during the 11th series release, the expiration date on the wall poster ad was changed from 12/31/74 to 7/30/75. The 21-fold wall poster wrapper with 1975 expiration date was definitely used for the 11th series, and that pack is pictured below.
Interestingly, the 1975 dated wall poster wrappers always occur on their own rolls. So full boxes of green packs contain either a mix of the 3 ad variations (id bracelet, jade necklace, '74 wall poster) or contain ALL '75 wall posters.
I have yet to determine whether the 85-fold wall poster wrapper with 1975 expiration date was used for series 11. It's definitely possible that it was. It's been difficult to be sure, because the 11th series 85-fold pack with '75 wall poster ad is probably the most frequently faked pack out there. I've examined (at last count) 5 copies of this pack that were all clear fakes, and have yet to find a legitimate one. The reason it's faked so often is that it's a very common wrapper (used for the 12th series) and a pretty valuable pack.
In fact, all green 11th series packs are very commonly found as fakes since the 85-fold 9th series wrappers are also very common. At one point, I had 7 of these packs and exactly one of them was legit. As I'll describe below, all of the green 11th series packs I have came from the same two sources. All 11th greens I've examined not from these sources have been fake.