I would like to know the name of these pieces.
The grey one (not the one with the towball socket)
(edit: found, it is 6009014 "Bracket 1 x 2 - 2 x 2") and the green one, they're similar but the grey one have the studs on the "inner" part, I think.
Edit: Found the grey one, still need the green.
The pieces are Bracket 1 x 2 - 2 x 2 and Bracket 1 x 2 - 2 x 2 Inverted. The grey piece is actually the inverted one.
The numbers should be printed underneath, then it's just a matter of finding the right colour e.g. look up part 44728 on BrickSet.com and you get http://brickset.com/parts/design-44728, then I'd say the right colour was dark green giving you http://brickset.com/parts/4212471
