If I walked into a store and they had a sign up stating they sold a product, yet when I asked about they told me they only have it maybe four months out of the year I would be a bit annoyed or confused.
I'm still not sure why the owner wouldn't allow anybody to take it down. Maybe it was hard to take down? Perhaps it was permanently stuck in the panel? All I know is that it was annoying always having to tell people that they couldn't order it because it was only a seasonal item. You'd think with as many requests as we received for it the owner would serve it all year long anyway.