hi emin j, the issue you describe sums up the missing 5 percent. I am completely in the same mindset as you my friend. Its very fustrating to say the least. No matter how many bir chefs post new material or print new books nothing really compares to that illusive taste.
I have concluded that its only partly to do with traditional indian cookery and those spices. I justify this because i have tried hundreds of traditional indian recipies , with base and without base ,by many chefs, and no matter what i do, it tastes nothing like a real TA. Not even close if i am being brutally honest. Traditional indian cookery spices are not the complete answer , there must be some thing else. Knowing about indigenous bangladesh cookery would be the best route to success, knowing all the vegetables, and other spices they use may help. shame not many books cover this.