Just as a reminder, they aren't stereoscopic if all you are doing is copying/pasting. You must think in terms of what your left eye sees, and what your right eye sees. Take/draw pictures of each eye's position, and put them together and THAT is stereoscopic imagery.
For example, here's a stereoscopic image made from a half life map; the left image has the camera moved only a few inches to the right. I put down a red dot just to have a point you can use to focus.
Large version (1920x540)
Because stereoscopic images involve crossing your eyes to see them, I'd suggest reversing the order of the images. The one taken a bit to the left goes on the right, and the image that is shifted over to the right should be put on the left.