Phil, One of the columns shown in the WSJT main window (where signals are decoded) is "DF". This stands for "delta frequency" and displays how many Hz +/- you must tune to be exactly on top of the decoded station.
As for logging RST, I always use OOO. It's weird for HF, yes, but is the standard signal report exchange for moonbounce. 73. -chris N2YYZ