Reality check: $\mathcal{O}_{\mathbb{P}_\mathbb{R}^1}(1)$ and $\mathcal{O}_{\mathbb{P}_\mathbb{R}^1}(-1)$ are both Möbius strips?

Leaving a community wiki answer to remove this from the unanswered list (once someone upvotes it): Yes, this is true. Georges Elencwacj edited his answer to another question in order to address this one.