Please refer to this articles and let us know if it helps: -
What is the pixel size of your video frames?
If you were to use Perspective Distort to straighten up each image first, you could then just stack them side by side:
That's an interesting idea. Have you tested it for real? I'm guessing you would need to resize the images after squaring them? Ahhh, I have just noticed that I misread your post. I thought you'd suggested using Perspective crop to square up the component images. I'll give that a try when I get a chance to collect some relevant photographs.