To play as notated, with the double-notes handled entirely by the right hand, I use this fingering:
measure 7: 14-25
measure 8: 13-25
measure 9: 14-25
measure 10: 13-25
measure 11: 13-25 or 12-25
measure 12: 13-25
However, as an alternative, the passage flows quite comfortably by splitting the inner voice between the two hands. In each measure, the right hand plays single notes on the beat and double-notes on the half-beats. The left hand does the opposite, playing double-notes on the beats and single notes on the half-beats.
Here is measure 7 as an example. For the right hand, I use 5-13, and for the left hand I use 13-5 correspondingly. (The first left-hand note, of course is 5: thus, 5-5 13-5 13-5 13-5.)