1. I obtained 'Letter of Recommendation' from Sir Lyndon at the quest of 'Shadow Dilos Latemn' https://i.imgur.com/4pKWSiY.png(for above)
1.1 Nunez takes the item 'Letter of Recommendation' when you get the quest 'Iller Style Tofu Dish' https://i.imgur.com/KXScDsr.jpg (for above)
1.2 Nunez gives you his 'Letter of Recommendation' when you finish 'Control Porto Bello'