Yes, the samurai armor that was lacquered is a toxic process. They didn't use "raw" leather. They hardened the leather scales because they lacked the ability to forge steel like the europeans could.
Like Sir Wolf said, there's not much as far as "historical" leather armor. Even 2,000 years ago they were using bronze, not leather.
If you want something functional that just "doesn't look like LARP", check the Viking Leathercrafts armor. They do full arms/shoulders/legs.