I pulled the back off of my (2) 2410's There is no VESA mount under the white plastic. I used small self tapping screws and put screws through the metal in 3 positions. I was hesitant to put a screw in over the board, but there is plenty of room for the other 3.
My suggestion is buy something VESA compliant. If you already have these pulling the ack off is easy. Remove the 3 screws holding the stand and then start at the top/side and pry off the white plastic.