If the place wasn't off limits otherwise, I think I'd follow the safest, most conservative path. I'd leave my gun in the holster without messing with it. Nobody would know, no one would be endangered, it would not be in violation of the law despite their gunbuster sign. Or so it seems to me.
I wouldn't open carry there.
Personally, I hate having to touch my gun. My preference is just leave the thing alone and quiet in the holster. I'm not disarmed, handling risks are minimized.