The Latin Spanish dub of One Piece was based on the 4 kids' English dub, this dub aired on Television Canal 5, Cartoon Network, 4 kids TV (via SAP audio) Etc... TV (still airing only subtitled), ATV, Televen, Chilevisión, etc...
After the acquisition of One Piece by Funimation, episodes weren't aired again on Cartoon Network, despite there's some recordings of recent dubbed airings on Chile, full episodes weren't recorded, and the internet pages only have the Castilian Spanish and fan subbed versions, making the dub harder to find.
Between 2018 and 2019, a Chilean YouTube user uploaded some commercial breaks from 2007 and 2008 of Etc. TV where some commercials of the series appear, considering that it is partially found.
On February 20, 2019, a user uploaded a video where Crocodile appears with the voice of Francisco Villasis complaining about something he doesn't like.
Also a dub of the One Piece Gold movie was done in Mexico and it's lost too, the only thing that was found of the movie is the trailer and the full cast
- Diana Pérez (eps. 1-52) and Karina Altamirano (eps 53-104): Luffy
- Alfredo Gabriel Basurto (eps 1-52 and kid version) and Dafnis Fernández (eps. 53-104): Zolo
- Georgina Sánchez: Nami
- Aldo Lugo: Usopp
- Noé Velázquez and an unknown actor (kid version): Sanji
- Nallely Solís: Tony Tony Chopper/Choppa
- Kerygma Flores: Nico Robin
EDIT: (MTVFAN2004 (Patra the Egypcian Fox Boyfriend)) I found 5 videos (4 of the commercials of Etc. TV and 1 of a famous user complaining about something he did not like):
EDIT 2: (SailorLarryBoy) One of my friends says that near to his house there's some bootleg anime DVD's. He said me that they're selling the One Piece Latin Spanish dub, I said him for buying these DVD'S for ripping them also the YouTube user EL PAKO haves clips of this dub
EDIT 3: (Nicolas creepy)
I found a folder on Google Drive with all the episodes in Latin Spanish, including the movie.