I'm confused about how Roger's letter to Bree, which he wrote in 1739, could later be in the hidden compartment of the drawer along with the 3 stamps. Previously we read that on discovering the hidden drawer, Bree & Roger found only the 3 stamps in it. I know Roger went back in time after this, but 1739 had already happened.
Another question, how does the desk, which was obviously in the Fraser family, (as it's mentioned when Roger is visiting Brian) get to be in Frank's posession - so that he can hide the letter to Bree in it?