Mix cucumbers and 3/4 teaspoon salt in strainer; let stand 15 minutes. Rinse well. Squeeze cucumbers dry. Wrap in kitchen towel to remove excess moisture.
Whisk 9 tablespoons plum sauce, vinegar and oil in large bowl to blend. Mix in turkey, green onions and chopped mint. Season with salt and pepper. Mix cucumbers into filling.
Fill another large bowl with hot water. Place 1 rice paper round in hot water until softened, about 30 seconds. Remove from water; place on towel and pat dry. Place 2 tablespoons filling in center of rice paper. Top with 1 mint leaf. Fold sides of rice paper over filling; roll up tightly. Repeat with remaining rice paper, filling and mint. (Can be made 6 hours ahead. Place spring rolls in single layer on platters. Cover with plastic; chill.)
