In One Piece Green: Secret Pieces an early concept of the crew was revealed. No changes in particular are seen in Luffy, Zoro, and Nami aside from a few small ones; such as Zoro carrying a bottle of sake on his waist and wearing a dark shirt rather than a white one, and Nami’s skirt being a little wavy rather than having straight cuts.

Sanji was supposed to have a somewhat thicker goatee from the beginning.
Usopp was supposed to be a vice captain/sniper that resembled his father more.
Chopper was supposed to be more of a “realistic-looking reindeer”.
Brook also was supposed to have a Cavalier hat, instead of his trademark afro.
The far left character is labeled “Shipbuilder”. He was supposed to be the shipwright and was replaced by Franky.
The second one from the left is labeled “Plant / Vegetation”. He was meant to be a plant obsessed character who was replaced by Nico Robin and largely incorporated into the post-timeskip Ussop.