[Solved]Weird shading on Media Stand

Remove doubles probably only makes it worse, as it removes the vertices splitting the edges. You need to make sure the front has separate vertices from the sides, and that the grab-bar oval inside is separate, too. When I separated this out from the rest of the front, the front went back to being flat. 

i.postimg.cc/g06XynjP/This-Piece.jpg

The other grab-bar doesn't have the issue, but the grab-bar is in several pieces and has a front and back layered on top of each other, so if you want them to match you may have to be a bit careful when selecting (I suggest selecting using L and not turning on the option to select back faces, and moving the mesh to check if you've selected the correct parts, then ctrl+Z to move back).

Just a side note, but you may want to take a look at the wheels, too - I noticed they looked a bit squished. If you scale them on the X-axis in the Front orthographic front view until they look more round, you'll get them back to normal. 

Here: simfileshare.net/download/1826301/

(wheel fix is included, too)

I marked the parts, then clicked P + enter (which makes the item entirely separate from the mesh), then joined the parts back together. That way you can be absolutely sure Blender does what you want it to do, which is to make a separate line of vertices in both ends of the grab-bar. 

That's weird. Did you do anything to the mesh after joining back together?

Remember you have to mark just the parts you want to separate out, like for instance the highlighted parts in the picture I posted above. If you mark the whole door and separate it from the rest of the mesh, it's not going to work.