Underwater wall?

[Popkin]

I am confused - I completed my fish and deep sea collections back in December (and have the golden rod) but the Underwater Wall has never shown up in the museum shop. Is there something I've missed? I've tried searching here and googling, but there doesn't seem to be anything else. (I could have over 100 each of the other museum wallpapers if I'd wanted...)

 

[Ami Mercury]

Just bad luck it isn't appearing I think.

 

[Reindeer]

I've completed my museum and I've yet to see the museum model show up in the shop. All I get is wallpapers, I haven't even seen any of the silver tools being sold lately.