i just received an email from tim addressing my concern about the orientation of transistors Q2, Q3, Q5, and Q6. he confirmed my suspicion that the "metal" side of these transistors should line up with the silkscreened double line on the board...in other words, the "metal" side of the transistors should be facing you (or down) when the board is place flat on a table.
i had a little trouble figuring that out, so i just wanted to throw this post up to help out anyone else who may be confused about that.