Could you put turps on your leather jacket to remove paint?

Definitely not recommended! If it is a hard leather with almost a waxy finish the turps will buckle the material and fade it, and soft leather will probably disintergrate. I've found (after leaving motorcycle leathers in the garage) that paint on leather is a killer. I found that by scratching off most of the paint with a new toothbrush and applying baby shampoo over night (just wipe of with wam water) will help lift most if not all paint off and if that fails apply a mild sugar soap (available from most hardware stores) will get the toughest of stains off but causes mild fading. Good luck!