Are there two filling plugs on an S320 rear diff?

[PJayUK]

Had a nose under my car in preperation for the job of draining and refilling my rear diff. I noticed that there appear to be two 14mm hex headed bolts on the top left and top right of the back diff (on the vertical back plate facing the back end of the car) both look like what has been described as the filling points.

Apologies for demonstrating my lack of MB experience but am I looking at the right thing are there indeed two of the blighters?

If so which on should I undo?

 

[Dieselman]

The filling plug should be on the side of the diff near the input shaft.