WORDS OF WARNING
The series is over a decade old and runs thousands of pages and thousands upon thousands of panels.
1. Oda's bound to reuse some ideas.
The cool thing about the spreads is that even though they're 'fake' he can grab something out of any of them whenever he wishes.
ie. Zoro wearing the 'Criminal' brand t-shirt years before we knew Camie would be in the main story.
2. Some things Oda draws are bound to unintentionally look or resemble his older work.
I don't think Oda was thinking about his Sanji riding a buffalo cover when he drew his Wanted Poster look-a-like Sanji riding a mechanically enhanced water buffalo.
Of course there's no way we can tell for sure but unless it's for certain, save the slaughtered lambs in his honor and spare the world unfounded OP Wikia entries.
For example, him reusing a fox with a mustache for a four-panel minor character doesn't scream LITERARY GENIUS but maybe that's just me. More like, "Haha! So he liked that idea huh?"